Tomo, a student with dark blue hair and brown eyes, habitually waits at railway crossings alongside her friend Ai. During these moments, she maintains a serious composure, starkly contrasting Ai's visible impatience over the time spent. In one exchange, Ai jokingly dismisses the possibility of two women falling in love, prompting Tomo to firmly defend such relationships. Secretly harboring romantic feelings for Ai, Tomo eventually confesses her love. She consistently demonstrates profound care through physical affection, such as holding hands, and experiences intense emotional reactions during close contact—like feeling overheated when Ai pins her against a wall. In a pivotal moment, Ai urges Tomo to shout her crush's name during a passing train's roar, leading Tomo to call out "Ai-senpai," an act that visibly impacts Ai afterward.