OVA
Description
Yakumo Tsukamoto is the younger sister of Tenma Tsukamoto. She enrolls at Yagami High School as a first-year in Class 1-D, progressing to Classes 2-D and 3-D. Born March 23, she begins the series at age 15, standing 166 cm tall with black hair, red eyes, and blood type AB. Her personality reflects quiet reserve and soft-spokenness, embodying the "yamato nadeshiko" ideal through diligent domestic skills in cooking, cleaning, and sewing. Academically and athletically gifted, she struggles specifically with skiing.

A psychic ability allows her to hear thoughts from individuals harboring deep affection for her, causing discomfort around admirers and contributing to social isolation. This power remains inactive toward those without romantic feelings directed at her, such as Kenji Harima, whose obsession with Tenma shields his thoughts. Consequently, Yakumo forms a uniquely unguarded bond with Harima, developing romantic feelings despite his focus on Tenma. His unreadable mind intrigues her, leading her to assist his manga career through professional inking and collaboration.

Childhood friction with Tenma arose when Tenma's clumsiness destroyed Yakumo's treasured possessions, including a book from their deceased father. A pivotal argument over this book resolved when Yakumo recalled their father's advice on family bonds, transforming their relationship into mutual protectiveness. Yakumo often assumes a caretaker role for Tenma, leading others to mistake her as the elder sister. She works part-time at Café Mercado, serving customers in seasonal cosplay attire.

Initially isolated by her beauty and mind-reading ability, Yakumo forms her first meaningful friendship when Sarah Adiemus rescues her from an aggressive dog—highlighting Yakumo's canine phobia. Sarah introduces her to the Tea Club, where Yakumo participates alongside Akira Takano after Haruki Hanai's exclusion. She interacts with Tenma's friends Eri Sawachika, Mikoto Suou, and Akira, though tensions flare with Eri over shared feelings for Harima. During the school Cultural Festival, Yakumo disrupts a staged kiss between Eri and Harima, though they later reach tentative understanding.

Interactions with Harima catalyze Yakumo's development from passivity to assertiveness. She confronts Eri over a misunderstanding involving Tenma and confesses her feelings to Harima, acknowledging his enduring love for her sister. An accidental kiss with Harima during the "Walking Festival" arc—while handcuffed—further strains relations with Eri. Despite her affection, Yakumo encourages Harima to pursue Eri as personal emotional release.

In the series' conclusion, Yakumo accepts Harima's impending marriage to Eri, leading to tearful resignation consoled by Tenma. After Tenma relocates to America to care for Karasuma, Yakumo lives with Sarah, maintains correspondence with Tenma, and embraces self-reliant independence. Her career aspirations shift toward clinical psychology or caregiving.

OVAs depict her reserved school life prior to friendships. One segment shows her aloofness and peer anxiety due to mind-reading, culminating in Sarah's dog-rescue intervention. Another features her assisting Harima during a manga deadline, sharing vulnerability during a power outage.

Yakumo cares for a stray black cat named Iori, preparing its meals daily. Their relationship evolves from tentative encounters to Iori becoming the Tsukamoto household pet, reflecting her animal affinity—a contrast to her recurring fear of dogs.