A naive classmate initially bullied by Naoko. Rio manipulates her into joining their clique and compensated dating scheme. Tomoko later shields Rio from Naoko's attack and reconciles with her after Rio confesses to orchestrating the bullying.
An antagonistic relationship rooted in jealousy and Naoko's mental breakdown.
Naoko attempts to stab Tomoko in class, accusing her of taking Rio away from her.
A complex friendship marked by manipulation, guilt, forgiveness, and mutual support.
After Rio confesses to orchestrating the bullying, Tomoko initially severs ties but they rekindle their friendship following Rio's collapse.
Explore the full interactive character relationship map of My Rainy Days