A first-year high school boy. He has no friends and possesses a detached, philosophical outlook on life. He is an otaku who loves light novels. While he intended to remain a mere bystander and live a peaceful life without making friends, he gets dragged into various troubles after witnessing Anna's heartbreak. He is strangely particular about the taste of the school's tap water. He is mentally stable but has a blunt, somewhat tactless personality. He doesn't speak much.

One of the losing heroines. Kazuhiko's classmate, popular due to her good looks. She has a bright and charming personality but can be a bit airheaded. She is also quite a glutton. She was in love with her childhood friend Sosuke, but he fell for the transfer student Karen Himemiya; Anna ended up supporting him, resulting in her own heartbreak. She considers her relationship with Kazuhiko to be that of "good partners" or "friends."

One of the losing heroines. Kazuhiko's classmate and the ace of the track and field club. Popular for her bright personality and athletic beauty. She isn't very good at studying. She was in love with her childhood friend Mitsuki, but he only saw her as a friend, leading to her heartbreak. A tanned, energetic girl. She lacks a sense of shame and thinks as long as she's somewhat covered, there's no problem.

One of the losing heroines. Kazuhiko's peer and a member of the Literature Club. She is extremely shy and struggles to talk to others. She was in love with Shintaro, who had encouraged her in the past, but his heart was not set on her. Notably, she is the only one among the losing heroines who gathered the courage to actually confess to the person she liked (Shintaro).

Karen's boyfriend and Anna's childhood friend. A handsome, cheerful, and prominent figure in class. However, he can be tone-deaf to social cues; he once tried to play matchmaker for Anna and Kazuhiko, which only made Anna angry.

Sosuke's girlfriend and Anna's best friend. She is beautiful and well-endowed, described by Kazuhiko as a "beautiful girl with the aura of a true main heroine." She has a kind heart and often worries about Anna. Unbeknownst to others, her relationship with Sosuke is actually quite intense.

Chihaya's boyfriend. He went to the same middle school and cram school as Kazuhiko, though they aren't exactly friends. He has known Lemon since elementary school. He is incredibly dense regarding romance; he didn't realize Lemon liked him, nor did he realize he had his first crush on her, until she finally spoke up.

Mitsuki's girlfriend. She used to attend the same cram school as Kazuhiko and was famous there for her beauty and excellent grades. While usually gentle, she has a stalker-like, jealous side. She is very knowledgeable about electronics and minerals.

A third-year high school student and president of the Literature Club. He is Koto's childhood friend. He is handsome and tall.

A third-year high school student and vice-president of the Literature Club. She is Shintaro's childhood friend. Her test scores are quite poor.