Nazotoki Yori mo Taihen da

A student named Eita Ichinose is invited to join a riddle-solving club by Saki Junjino, a highly capable and popular senior known for her interest in riddles. Each day after school, Eita works to solve the puzzles she presents. His continued participation is motivated by a desire to spend time with her. The riddles do not rely on prior knowledge or mathematical ability, making them accessible to attempt independently.