A member of the Classics Club. Class 1-B. An energy-saver whose motto is, "If I don't have to do it, I won't. If I have to do it, I'll make it quick." Despite this, he possesses exceptional insight and deductive reasoning. He joined the Classics Club, which was on the verge of being disbanded, at the recommendation (threat) of his older sister.

The president of the Classics Club. Class 1-A. A young lady from a prestigious family who joined the club for personal reasons. She possesses the refined, elegant appearance of a high-born lady, paired with lively eyes that contrast her status. While she is usually soft-spoken and polite, once she encounters a minor inconsistency or something that piques her interest in daily life, her large eyes sparkle and she becomes curiosity incarnate. Her catchphrase is "I'm curious!"

Hotaro's best friend and a member of both the Classics Club and the Handicrafts Club. A classmate of Guest. He is shorter than the average boy and could be mistaken for a girl from a distance, but his legs are well-trained from his hobby of cycling. He almost never loses his smiling expression. His catchphrase is "A database cannot draw conclusions." Since he belongs to both the Handicrafts and Classics clubs, he is well-known throughout the school and has many acquaintances. He is the type who isn't shy around strangers.

A first-year student (class unknown). A member of the Classics Club. She was already a member of the Manga Research Society and the Library Committee, but she followed Satoshi into the Classics Club as well. She is short with a baby face, and her appearance has hardly changed since elementary school. Contrary to her looks, she has a fierce personality, a sharp tongue, and is uncompromising toward both herself and the mistakes of others.

Class 1-D. A classmate of Guest. The sole member and president of the Fortune Telling Research Society. Her family runs the prestigious Arekus Shrine in Kamiyama City. She is highly knowledgeable and loves the library so much that Satoshi describes her as the "new master of the library."