diff --git a/prisma/tasks.ts b/prisma/tasks.ts
index 657357df0..25279adb2 100755
--- a/prisma/tasks.ts
+++ b/prisma/tasks.ts
@@ -8256,6 +8256,132 @@ export const tasks = [
     name: 'Reachable Towns',
     title: 'A. Reachable Towns',
   },
+  {
+    id: 'ddcc2020_qual_f',
+    contest_id: 'ddcc2020-qual',
+    problem_index: 'F',
+    name: 'DISCOSMOS',
+    title: 'F. DISCOSMOS',
+  },
+  {
+    id: 'ddcc2020_qual_e',
+    contest_id: 'ddcc2020-qual',
+    problem_index: 'E',
+    name: 'Majority of Balls',
+    title: 'E. Majority of Balls',
+  },
+  {
+    id: 'ddcc2020_qual_d',
+    contest_id: 'ddcc2020-qual',
+    problem_index: 'D',
+    name: 'Digit Sum Replace',
+    title: 'D. Digit Sum Replace',
+  },
+  {
+    id: 'ddcc2020_qual_c',
+    contest_id: 'ddcc2020-qual',
+    problem_index: 'C',
+    name: 'Strawberry Cakes',
+    title: 'C. Strawberry Cakes',
+  },
+  {
+    id: 'ddcc2020_qual_b',
+    contest_id: 'ddcc2020-qual',
+    problem_index: 'B',
+    name: 'Iron Bar Cutting',
+    title: 'B. Iron Bar Cutting',
+  },
+  {
+    id: 'ddcc2020_qual_a',
+    contest_id: 'ddcc2020-qual',
+    problem_index: 'A',
+    name: 'DDCC Finals',
+    title: 'A. DDCC Finals',
+  },
+  {
+    id: 'nikkei2019_2_qual_f',
+    contest_id: 'nikkei2019-2-qual',
+    problem_index: 'F',
+    name: 'Mirror Frame',
+    title: 'F. Mirror Frame',
+  },
+  {
+    id: 'nikkei2019_2_qual_e',
+    contest_id: 'nikkei2019-2-qual',
+    problem_index: 'E',
+    name: 'Non-triangular Triplets',
+    title: 'E. Non-triangular Triplets',
+  },
+  {
+    id: 'nikkei2019_2_qual_d',
+    contest_id: 'nikkei2019-2-qual',
+    problem_index: 'D',
+    name: 'Shortest Path on a Line',
+    title: 'D. Shortest Path on a Line',
+  },
+  {
+    id: 'nikkei2019_2_qual_c',
+    contest_id: 'nikkei2019-2-qual',
+    problem_index: 'C',
+    name: 'Swaps',
+    title: 'C. Swaps',
+  },
+  {
+    id: 'nikkei2019_2_qual_b',
+    contest_id: 'nikkei2019-2-qual',
+    problem_index: 'B',
+    name: 'Counting of Trees',
+    title: 'B. Counting of Trees',
+  },
+  {
+    id: 'nikkei2019_2_qual_a',
+    contest_id: 'nikkei2019-2-qual',
+    problem_index: 'A',
+    name: 'Sum of Two Integers',
+    title: 'A. Sum of Two Integers',
+  },
+  {
+    id: 'diverta2019_2_f',
+    contest_id: 'diverta2019-2',
+    problem_index: 'F',
+    name: 'Diverta City',
+    title: 'F. Diverta City',
+  },
+  {
+    id: 'diverta2019_2_e',
+    contest_id: 'diverta2019-2',
+    problem_index: 'E',
+    name: 'Balanced Piles',
+    title: 'E. Balanced Piles',
+  },
+  {
+    id: 'diverta2019_2_d',
+    contest_id: 'diverta2019-2',
+    problem_index: 'D',
+    name: 'Squirrel Merchant',
+    title: 'D. Squirrel Merchant',
+  },
+  {
+    id: 'diverta2019_2_c',
+    contest_id: 'diverta2019-2',
+    problem_index: 'C',
+    name: 'Successive Subtraction',
+    title: 'C. Successive Subtraction',
+  },
+  {
+    id: 'diverta2019_2_b',
+    contest_id: 'diverta2019-2',
+    problem_index: 'B',
+    name: 'Picking Up',
+    title: 'B. Picking Up',
+  },
+  {
+    id: 'diverta2019_2_a',
+    contest_id: 'diverta2019-2',
+    problem_index: 'A',
+    name: 'Ball Distribution',
+    title: 'A. Ball Distribution',
+  },
   {
     id: 'tenka1_2019_f',
     contest_id: 'tenka1-2019',
diff --git a/src/lib/contests/fixtures/contest_type.ts b/src/lib/contests/fixtures/contest_type.ts
index 32663ea60..c8b3670a0 100644
--- a/src/lib/contests/fixtures/contest_type.ts
+++ b/src/lib/contests/fixtures/contest_type.ts
@@ -300,6 +300,10 @@ export const arcLike = [
     contestId: 'diverta2019',
     expected: ContestType.ARC_LIKE,
   }),
+  createTestCaseForContestType('diverta 2019 Programming Contest 2')({
+    contestId: 'diverta2019-2',
+    expected: ContestType.ARC_LIKE,
+  }),
   createTestCaseForContestType('KEYENCE2019')({
     contestId: 'keyence2019',
     expected: ContestType.ARC_LIKE,
@@ -320,6 +324,14 @@ export const arcLike = [
     contestId: 'nikkei2019-qual',
     expected: ContestType.ARC_LIKE,
   }),
+  createTestCaseForContestType('NIKKEI2019-2 QUAL')({
+    contestId: 'nikkei2019-2-qual',
+    expected: ContestType.ARC_LIKE,
+  }),
+  createTestCaseForContestType('DDCC2020 QUAL')({
+    contestId: 'ddcc2020-qual',
+    expected: ContestType.ARC_LIKE,
+  }),
   createTestCaseForContestType('ACL1')({
     contestId: 'acl1',
     expected: ContestType.ARC_LIKE,
diff --git a/src/lib/contests/utils/prefixes.ts b/src/lib/contests/utils/prefixes.ts
index 2956400e0..e3a94ce86 100644
--- a/src/lib/contests/utils/prefixes.ts
+++ b/src/lib/contests/utils/prefixes.ts
@@ -3,8 +3,9 @@ import type { ContestPrefix } from '$lib/contests/types/contest';
 export const regexForJag = /^JAG(Prelim|Regional|Summer|Winter|Spring)\d{4}(-day\d+)?[A-Z]?$/;
 export const regexForAojUniversity = /^AOJ-[A-Z]+PC\d{4}/;
 
-// HACK: As of December 2025, the following contests are applicable.
+// HACK: As of October 2026, the following contests are applicable.
 // Note: The classification logic may need to be revised when new contests are added.
+// ABC_LIKE / ARC_LIKE: exact match — add sequels (e.g. diverta2019-2) explicitly. Others: prefix match.
 export const ABC_LIKE: ContestPrefix = {
   'tenka1-2017-beginner': 'Tenka1 Programmer Beginner Contest 2017',
   abl: 'ACL Beginner Contest',
@@ -31,11 +32,14 @@ export const ARC_LIKE: ContestPrefix = {
   'dwacon5th-prelims': '第5回 ドワンゴからの挑戦状 予選',
   'dwacon6th-prelims': '第6回 ドワンゴからの挑戦状 予選',
   diverta2019: 'diverta 2019 Programming Contest',
+  'diverta2019-2': 'diverta 2019 Programming Contest 2',
   keyence2019: 'キーエンス プログラミング コンテスト 2019',
   keyence2020: 'キーエンス プログラミング コンテスト 2020',
   keyence2021: 'キーエンス プログラミング コンテスト 2021',
   'jsc2019-qual': '第一回日本最強プログラマー学生選手権-予選-',
   'nikkei2019-qual': '全国統一プログラミング王決定戦予選',
+  'nikkei2019-2-qual': '第二回全国統一プログラミング王決定戦予選',
+  'ddcc2020-qual': 'DISCO presents ディスカバリーチャンネル コードコンテスト2020 予選',
   acl1: 'ACL Contest 1',
 } as const;