TV-Series
Description
Hougetsu Shimamura is a 15-year-old high school student whose bond with Sakura Adachi began when both skipped class and met in the gymnasium loft. Their first encounter varies across source materials, sometimes depicting Shimamura discovering Adachi first. This meeting forged a connection as kindred spirits, their friendship growing through repeated meetings in that space.

Shimamura has tailbone-length hair, originally black but dyed light brown, typically secured with two clips on the right side. Over time, it reverts to its natural color. She possesses brown eyes and a slim build, standing shorter than Adachi despite her middle school basketball experience. She acknowledges having "love handles," which both Adachi and the self-proclaimed alien Yashiro sometimes touch, much to her annoyance.

Her personality centers on finding human relationships burdensome due to the effort required to maintain them. Laziness, absent-mindedness, and a tendency to avoid emotional investment characterize her outlook, viewing most social connections as transient. This stems from middle school experiences where surface-level friendships dissolved after class changes, leading her to adopt a passive "go with the flow" approach. She questions whether caring for her younger sister is genuine affection or perceived duty and dislikes her surname due to its association with a clothing brand, preferring "Shimazaki."

Shimamura undergoes significant development. Initially dismissive of deep connections, she quickly recognizes Adachi as irreplaceable. Their bond challenges her disengagement, culminating in accepting Adachi's romantic confession during their second-year summer festival. Though calm and rational about dating initially, her emotional investment deepens in later volumes. She experiences a love epiphany, realizing her feelings differ in expression but not intensity from Adachi's. This motivates her to actively preserve their relationship, fearing separation.

Her background reveals a more outgoing childhood marked by strong attachment to her grandparents' dog, Gon, whose demeanor sometimes reminded her of Adachi. In elementary school, she befriended Tarumi, nicknaming each other "Shima-chan" and "Taru-chan," but they drifted apart in junior high after attending different schools. Reconnecting with Tarumi in high school highlights Shimamura's reluctance to revisit past ties, though she acknowledges Tarumi's lingering significance.

Shimamura's relationship dynamics mature. She transitions from playfully teasing Adachi—comparing her to a dog and relishing flustered reactions—to seeking mutual equality. She refuses Adachi's financial support for joint activities, rejecting perceptions of being a "gold digger." Flash-forwards depict them sustaining their relationship into adulthood, cohabiting and vacationing as equals. By volume 10, Shimamura notes Adachi's slightly expanded social circle after ten years together, though Adachi remains her closest partner.

Family interactions include enduring her mother's playful teasing, which embarrasses her in front of Adachi. Her mother favors others over her, humorously labeling Shimamura's lunch as "delinquent" while personalizing Adachi's. Shimamura shares her mother's teasing trait but tempers it with consideration for others' sensitivities.