May 2026’s Korean book charts did not produce one clean national No. 1 across Kyobo Book Centre, Yes24, and Aladin. What they did show was a repeat pattern: fiction remained unusually visible through 프로젝트 헤일메리 (Project Hail Mary), 안녕이라 그랬어 (I Said Goodbye), and durable literary backlist, while nonfiction widened into communication psychology, finance, philosophy, and exam-prep rather than narrowing into one dominant essay cluster.

Fiction Bestsellers in Korea

Fiction remained commercially loud in May, but it did so through a mixed field rather than a single winner. Adaptation-fueled translated fiction, Korean literary fiction, and long-running classics all stayed visible at once.

Yes24 Fiction Bestsellers

1. 프로젝트 헤일메리 (Project Hail Mary) — visible on Yes24’s monthly bestseller surface, and singled out by Yes24’s official first-half trend page as the platform’s No. 1 overall book for the half-year.
2. 안녕이라 그랬어 (I Said Goodbye) — visible on the monthly bestseller surface with strong sales index and continuing literary visibility.
3. 싯다르타 (Siddhartha) — also visible on the monthly bestseller surface, showing that classic literary backlist was still traveling with May demand rather than disappearing behind only new releases.

Aladin Fiction Bestsellers

1. 싯다르타 (Siddhartha) — No. 3 overall.
2. 프로젝트 헤일메리 (Project Hail Mary) — No. 4 overall.
3. 안녕이라 그랬어 (I Said Goodbye) — No. 7 overall.
4. 1938 타이완 여행기 (1938 Taiwan Travelogue) — No. 9 overall.
5. 나는 고양이로소이다 (I Am a Cat), limited edition — No. 18 overall.
6. 백지 앞에서 (Before the Blank Page) — No. 19 overall.
7. 모순 (Contradiction) — No. 20 overall.

Nonfiction Bestsellers in Korea

May nonfiction was practical, crowded, and slightly less coherent than fiction. The strongest visible books promised communication skills, mental steadiness, financial planning, world knowledge, or exam advantage rather than one narrowly shared emotional mood.

Yes24 Nonfiction Bestsellers

1. 품격 있는 대화를 위한 지식 브리핑 (Knowledge Briefing for Dignified Conversation) — visible high on the monthly bestseller surface.
2. 사춘기 엄마의 오장육부 (The Inner Life of a Mother Raising a Teenager) — also visibly high on the monthly page.
3. 내면 근력 (Inner Strength) — visible with strong sales index on the monthly page.
4. 프로젝트 헤일메리 (Project Hail Mary) remained on the same mixed overall monthly surface, which is another reminder that fiction still cut through an otherwise nonfiction-heavy practical market.
5. 박곰희 연금 부자 수업 (Park Gomhee’s Pension Wealth Class) — visible on the monthly page with strong ongoing sales.
6. 니체의 초월자 (Nietzsche’s Transcender) — visible on the monthly page as a philosophy/self-cultivation title.
7. 말하지 않고 말하기 (Speaking Without Speaking) — visible on the monthly page as a new communication-psychology title.

What stands out on Yes24 is how broad the practical-reading field became. Communication skills, parenting stress, finance, philosophy, and emotional steadiness all occupied meaningful space on the same monthly surface.

Aladin Nonfiction Bestsellers

1. 사춘기 엄마의 오장육부 (The Inner Life of a Mother Raising a Teenager) — No. 5 overall.
2. 말하지 않고 말하기 (Speaking Without Speaking) — No. 6 overall.
3. 박곰희 연금 부자 수업 (Park Gomhee’s Pension Wealth Class) — No. 8 overall.
4. 품격 있는 대화를 위한 지식 브리핑 (Knowledge Briefing for Dignified Conversation) — No. 10 overall.
5. 최소한의 세계사 (The Minimum World History) — No. 11 overall.
6. 김미경의 플러스 휴먼 (Kim Mi-kyung’s Plus Human) — No. 13 overall.
7. 내면 근력 (Inner Strength) — No. 15 overall.
8. 니체의 초월자 (Nietzsche’s Transcender) — No. 16 overall.
9. 2026 선재국어 최우선 봉투 모의고사 (2026 Seonjae Korean Priority Mock Exam Pack) — No. 17 overall.
10. 인생을 위한 최소한의 생각 (The Minimum Thoughts for Life) — No. 31 overall.

Aladin’s nonfiction read is the strongest evidence that May was not a simple “healing essay” month. The upper band mixed communication psychology, pension planning, general knowledge, AI-and-career anxiety, philosophy, and test prep. That is a more utilitarian and more crowded nonfiction market than the tighter reflective clusters seen earlier in spring.

Monthly Trends in Korean Books

Fiction kept its unusual strength

Yes24’s official first-half report says fiction returned forcefully, with novels taking 22 places in the overall top 100 and Project Hail Mary leading the first-half overall chart. That broader fiction rebound still showed up in the May-weighted retailer environment.

The adaptation effect did not disappear

프로젝트 헤일메리 (Project Hail Mary) remained one of the clearest crossover titles in the market. It stayed visible on Yes24’s monthly surface and sat at No. 4 on Aladin’s rolling monthly overall chart. May was therefore not a one-week adaptation spike; the title still carried weight deep into the next reporting cycle.

Korean literary fiction held its space

안녕이라 그랬어 (I Said Goodbye) stayed visible on Yes24’s monthly surface and ranked No. 7 on Aladin’s rolling monthly list. At the same time, 백지 앞에서 (Before the Blank Page) and 모순 (Contradiction) showed that Korean literary fiction ranged from newer releases to established backlist.

Classics moved alongside new books

Aladin’s top 20 included 싯다르타 (Siddhartha) at No. 3, 나는 고양이로소이다 (I Am a Cat) at No. 18, and 모순 (Contradiction) at No. 20. That is not the profile of a market driven only by novelty. Readers were still buying recognizable classics and long-lived titles alongside spring releases.

Nonfiction shifted toward usable knowledge

On both Yes24 and Aladin, the strongest nonfiction titles were built around use: how to speak, how to think, how to manage a career, how to plan retirement, how to handle exams, how to orient yourself intellectually. Books like 말하지 않고 말하기 (Speaking Without Speaking), 품격 있는 대화를 위한 지식 브리핑 (Knowledge Briefing for Dignified Conversation), 박곰희 연금 부자 수업 (Park Gomhee’s Pension Wealth Class), and 최소한의 세계사 (The Minimum World History) all fit that pattern.

Philosophy remained commercial, not niche

니체의 초월자 (Nietzsche’s Transcender) stayed visible on Yes24’s monthly surface and ranked No. 16 on Aladin’s rolling monthly chart, while 인생을 위한 최소한의 생각 (The Minimum Thoughts for Life) still held a place inside Aladin’s top 40. Philosophy and practical thinking were still being bought as mainstream personal-orientation books, not as narrow academic reading.

Test-prep was part of the same reading month

Exam books did not sit outside the market story. On Aladin, 2026 선재국어 최우선 봉투 모의고사 (2026 Seonjae Korean Priority Mock Exam Pack) ranked No. 17, and deeper in the chart 2026 큰별쌤 최태성의 별★별한국사… (2026 Choi Tae-sung’s Byeolbyeol Korean History…) also remained visible. That makes May’s nonfiction field more seasonal and utilitarian than a pure leisure-reading snapshot.

What Changed From April

A precise April-versus-May retailer comparison is only partly visible from the accessible pages, so the safest comparison is directional rather than absolute. The clearest holdover was 프로젝트 헤일메리 (Project Hail Mary), which still anchored the fiction conversation in May. So did 안녕이라 그랬어 (I Said Goodbye), which remained visible across retailers instead of disappearing after an earlier surge.

The clearest May change was broader nonfiction turnover. Newer spring books such as 말하지 않고 말하기 (Speaking Without Speaking), 최소한의 세계사 (The Minimum World History), and 김미경의 플러스 휴먼 (Kim Mi-kyung’s Plus Human) entered the upper monthly field, while finance, communication, and exam-prep titles crowded the same band as philosophy and reflective nonfiction. That makes May look more utility-led than a narrowly essay-led month.