diff --git a/src/main/kotlin/org/koitharu/kotatsu/parsers/site/DesuMeParser.kt b/src/main/kotlin/org/koitharu/kotatsu/parsers/site/DesuMeParser.kt
index 3b76baed..3004dcc4 100644
--- a/src/main/kotlin/org/koitharu/kotatsu/parsers/site/DesuMeParser.kt
+++ b/src/main/kotlin/org/koitharu/kotatsu/parsers/site/DesuMeParser.kt
@@ -1,5 +1,6 @@
 package org.koitharu.kotatsu.parsers.site
 
+import androidx.collection.ArrayMap
 import org.koitharu.kotatsu.parsers.MangaLoaderContext
 import org.koitharu.kotatsu.parsers.MangaSourceParser
 import org.koitharu.kotatsu.parsers.PagedMangaParser
@@ -15,147 +16,165 @@ import java.util.*
 @MangaSourceParser("DESUME", "Desu.me", "ru")
 internal class DesuMeParser(context: MangaLoaderContext) : PagedMangaParser(context, MangaSource.DESUME, 20) {
 
-    override val configKeyDomain = ConfigKey.Domain("desu.me", null)
+	override val configKeyDomain = ConfigKey.Domain("desu.me", null)
 
-    override val sortOrders: Set<SortOrder> = EnumSet.of(
-        SortOrder.UPDATED,
-        SortOrder.POPULARITY,
-        SortOrder.NEWEST,
-        SortOrder.ALPHABETICAL,
-    )
+	override val sortOrders: Set<SortOrder> = EnumSet.of(
+		SortOrder.UPDATED,
+		SortOrder.POPULARITY,
+		SortOrder.NEWEST,
+		SortOrder.ALPHABETICAL,
+	)
 
-    override suspend fun getListPage(
-        page: Int,
-        query: String?,
-        tags: Set<MangaTag>?,
-        sortOrder: SortOrder,
-    ): List<Manga> {
-        if (query != null && page != searchPaginator.firstPage) {
-            return emptyList()
-        }
-        val domain = domain
-        val url = buildString {
-            append("https://")
-            append(domain)
-            append("/manga/api/?limit=20&order=")
-            append(getSortKey(sortOrder))
-            append("&page=")
-            append(page)
-            if (!tags.isNullOrEmpty()) {
-                append("&genres=")
-                appendAll(tags, ",") { it.key }
-            }
-            if (query != null) {
-                append("&search=")
-                append(query)
-            }
-        }
-        val json = webClient.httpGet(url).parseJson().getJSONArray("response")
-            ?: throw ParseException("Invalid response", url)
-        val total = json.length()
-        val list = ArrayList<Manga>(total)
-        for (i in 0 until total) {
-            val jo = json.getJSONObject(i)
-            val cover = jo.getJSONObject("image")
-            val id = jo.getLong("id")
-            list += Manga(
-                url = "/manga/api/$id",
-                publicUrl = jo.getString("url"),
-                source = MangaSource.DESUME,
-                title = jo.getString("russian"),
-                altTitle = jo.getString("name"),
-                coverUrl = cover.getString("preview"),
-                largeCoverUrl = cover.getString("original"),
-                state = when {
-                    jo.getInt("ongoing") == 1 -> MangaState.ONGOING
-                    else -> null
-                },
-                rating = jo.getDouble("score").toFloat().coerceIn(0f, 1f),
-                id = generateUid(id),
-                isNsfw = false,
-                tags = emptySet(),
-                author = null,
-                description = jo.getString("description"),
-            )
-        }
-        return list
-    }
+	private val tagsCache = SuspendLazy(::fetchTags)
 
-    override suspend fun getDetails(manga: Manga): Manga {
-        val url = manga.url.toAbsoluteUrl(domain)
-        val json = webClient.httpGet(url).parseJson().getJSONObject("response")
-            ?: throw ParseException("Invalid response", url)
-        val baseChapterUrl = manga.url + "/chapter/"
-        val chaptersList = json.getJSONObject("chapters").getJSONArray("list")
-        val totalChapters = chaptersList.length()
-        return manga.copy(
-            tags = json.getJSONArray("genres").mapJSONToSet {
-                MangaTag(
-                    key = it.getString("text"),
-                    title = it.getString("russian").toTitleCase(),
-                    source = manga.source,
-                )
-            },
-            publicUrl = json.getString("url"),
-            description = json.getString("description"),
-            chapters = chaptersList.mapJSONIndexed { i, it ->
-                val chid = it.getLong("id")
-                val volChap = "Том " + it.optString("vol", "0") + ". " + "Глава " + it.optString("ch", "0")
-                val title = it.optString("title", "null").takeUnless { it == "null" }
-                MangaChapter(
-                    id = generateUid(chid),
-                    source = manga.source,
-                    url = "$baseChapterUrl$chid",
-                    uploadDate = it.getLong("date") * 1000,
-                    name = if (title.isNullOrEmpty()) volChap else "$volChap: $title",
-                    number = totalChapters - i,
-                    scanlator = null,
-                    branch = null,
-                )
-            }.reversed(),
-        )
-    }
+	override suspend fun getListPage(
+		page: Int,
+		query: String?,
+		tags: Set<MangaTag>?,
+		sortOrder: SortOrder,
+	): List<Manga> {
+		if (query != null && page != searchPaginator.firstPage) {
+			return emptyList()
+		}
+		val domain = domain
+		val url = buildString {
+			append("https://")
+			append(domain)
+			append("/manga/api/?limit=20&order=")
+			append(getSortKey(sortOrder))
+			append("&page=")
+			append(page)
+			if (!tags.isNullOrEmpty()) {
+				append("&genres=")
+				appendAll(tags, ",") { it.key }
+			}
+			if (query != null) {
+				append("&search=")
+				append(query)
+			}
+		}
+		val json = webClient.httpGet(url).parseJson().getJSONArray("response")
+			?: throw ParseException("Invalid response", url)
+		val total = json.length()
+		val list = ArrayList<Manga>(total)
+		val tagsMap = tagsCache.tryGet().getOrNull()
+		for (i in 0 until total) {
+			val jo = json.getJSONObject(i)
+			val cover = jo.getJSONObject("image")
+			val id = jo.getLong("id")
+			val genres = jo.getString("genres").split(',')
+			list += Manga(
+				url = "/manga/api/$id",
+				publicUrl = jo.getString("url"),
+				source = MangaSource.DESUME,
+				title = jo.getString("russian"),
+				altTitle = jo.getString("name"),
+				coverUrl = cover.getString("preview"),
+				largeCoverUrl = cover.getString("original"),
+				state = when {
+					jo.getInt("ongoing") == 1 -> MangaState.ONGOING
+					else -> null
+				},
+				rating = jo.getDouble("score").toFloat().coerceIn(0f, 1f),
+				id = generateUid(id),
+				isNsfw = false,
+				tags = if (!tagsMap.isNullOrEmpty()) {
+					genres.mapNotNullToSet { g ->
+						tagsMap[g.trim().toTitleCase()]
+					}
+				} else {
+					emptySet()
+				},
+				author = null,
+				description = jo.getString("description"),
+			)
+		}
+		return list
+	}
 
-    override suspend fun getPages(chapter: MangaChapter): List<MangaPage> {
-        val fullUrl = chapter.url.toAbsoluteUrl(domain)
-        val json = webClient.httpGet(fullUrl)
-            .parseJson()
-            .getJSONObject("response") ?: throw ParseException("Invalid response", fullUrl)
-        return json.getJSONObject("pages").getJSONArray("list").mapJSON { jo ->
-            MangaPage(
-                id = generateUid(jo.getLong("id")),
-                referer = fullUrl,
-                preview = null,
-                source = chapter.source,
-                url = jo.getString("img"),
-            )
-        }
-    }
+	override suspend fun getDetails(manga: Manga): Manga {
+		val url = manga.url.toAbsoluteUrl(domain)
+		val json = webClient.httpGet(url).parseJson().getJSONObject("response")
+			?: throw ParseException("Invalid response", url)
+		val baseChapterUrl = manga.url + "/chapter/"
+		val chaptersList = json.getJSONObject("chapters").getJSONArray("list")
+		val totalChapters = chaptersList.length()
+		return manga.copy(
+			tags = json.getJSONArray("genres").mapJSONToSet {
+				MangaTag(
+					key = it.getString("text"),
+					title = it.getString("russian").toTitleCase(),
+					source = manga.source,
+				)
+			},
+			publicUrl = json.getString("url"),
+			description = json.getString("description"),
+			chapters = chaptersList.mapJSONIndexed { i, it ->
+				val chid = it.getLong("id")
+				val volChap = "Том " + it.optString("vol", "0") + ". " + "Глава " + it.optString("ch", "0")
+				val title = it.optString("title", "null").takeUnless { it == "null" }
+				MangaChapter(
+					id = generateUid(chid),
+					source = manga.source,
+					url = "$baseChapterUrl$chid",
+					uploadDate = it.getLong("date") * 1000,
+					name = if (title.isNullOrEmpty()) volChap else "$volChap: $title",
+					number = totalChapters - i,
+					scanlator = null,
+					branch = null,
+				)
+			}.reversed(),
+		)
+	}
 
-    override suspend fun getTags(): Set<MangaTag> {
-        val doc = webClient.httpGet("https://${domain}/manga/").parseHtml()
-        val root = doc.body().requireElementById("animeFilter")
-            .selectFirstOrThrow(".catalog-genres")
-        return root.select("li").mapToSet {
-            val input = it.selectFirstOrThrow("input")
-            MangaTag(
-                source = source,
-                key = input.attr("data-genre-slug").ifEmpty {
-                    it.parseFailed("data-genre-slug is empty")
-                },
-                title = input.attr("data-genre-name").toTitleCase().ifEmpty {
-                    it.parseFailed("data-genre-name is empty")
-                },
-            )
-        }
-    }
+	override suspend fun getPages(chapter: MangaChapter): List<MangaPage> {
+		val fullUrl = chapter.url.toAbsoluteUrl(domain)
+		val json = webClient.httpGet(fullUrl)
+			.parseJson()
+			.getJSONObject("response") ?: throw ParseException("Invalid response", fullUrl)
+		return json.getJSONObject("pages").getJSONArray("list").mapJSON { jo ->
+			MangaPage(
+				id = generateUid(jo.getLong("id")),
+				referer = fullUrl,
+				preview = null,
+				source = chapter.source,
+				url = jo.getString("img"),
+			)
+		}
+	}
 
-    private fun getSortKey(sortOrder: SortOrder) =
-        when (sortOrder) {
-            SortOrder.ALPHABETICAL -> "name"
-            SortOrder.POPULARITY -> "popular"
-            SortOrder.UPDATED -> "updated"
-            SortOrder.NEWEST -> "id"
-            else -> "updated"
-        }
+	override suspend fun getTags(): Set<MangaTag> {
+		return tagsCache.get().values.toSet()
+	}
+
+	private fun getSortKey(sortOrder: SortOrder) =
+		when (sortOrder) {
+			SortOrder.ALPHABETICAL -> "name"
+			SortOrder.POPULARITY -> "popular"
+			SortOrder.UPDATED -> "updated"
+			SortOrder.NEWEST -> "id"
+			else -> "updated"
+		}
+
+	private suspend fun fetchTags(): Map<String, MangaTag> {
+		val doc = webClient.httpGet("https://${domain}/manga/").parseHtml()
+		val root = doc.body().requireElementById("animeFilter")
+			.selectFirstOrThrow(".catalog-genres")
+		val li = root.select("li")
+		val result = ArrayMap<String, MangaTag>(li.size)
+		li.forEach {
+			val input = it.selectFirstOrThrow("input")
+			val tag = MangaTag(
+				source = source,
+				key = input.attr("data-genre-slug").ifEmpty {
+					it.parseFailed("data-genre-slug is empty")
+				},
+				title = input.attr("data-genre-name").toTitleCase().ifEmpty {
+					it.parseFailed("data-genre-name is empty")
+				},
+			)
+			result[tag.title] = tag
+		}
+		return result
+	}
 }
diff --git a/src/main/kotlin/org/koitharu/kotatsu/parsers/util/SuspendLazy.kt b/src/main/kotlin/org/koitharu/kotatsu/parsers/util/SuspendLazy.kt
new file mode 100644
index 00000000..cb9a911a
--- /dev/null
+++ b/src/main/kotlin/org/koitharu/kotatsu/parsers/util/SuspendLazy.kt
@@ -0,0 +1,36 @@
+package org.koitharu.kotatsu.parsers.util
+
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+
+class SuspendLazy<T>(
+	private val initializer: suspend () -> T,
+) {
+
+	private val mutex = Mutex()
+	private var cachedValue: Any? = Uninitialized
+
+	@Suppress("UNCHECKED_CAST")
+	suspend fun get(): T {
+		// fast way
+		cachedValue.let {
+			if (it !== Uninitialized) {
+				return it as T
+			}
+		}
+		return mutex.withLock {
+			cachedValue.let {
+				if (it !== Uninitialized) {
+					return it as T
+				}
+			}
+			val result = initializer()
+			cachedValue = result
+			result
+		}
+	}
+
+	suspend fun tryGet() = runCatchingCancellable { get() }
+
+	private object Uninitialized
+}