Tsuyu Asui, known as "Tsu" to friends, exhibits a frog-inspired Quirk enabling wall-climbing, a 20-meter extendable tongue, camouflage, versatile mucus secretion, and swift aquatic movement. Her physiology falters in extreme cold, risking hibernation. Childhood responsibilities caring for siblings Samidare and Satsuki, amid her parents’ absence, cultivated her self-reliant nature. Socially isolated in middle school due to her appearance and hectic schedule, she bridged solitude by befriending fellow outcast Habuko Mongoose, patiently navigating Habuko’s initial defiance. At U.A. High, her tactical intellect and unflappable demeanor proved critical during crises. She strategized Midoriya and Mineta’s escape from aquatic foes at U.S.J., later privately theorizing Midoriya’s Quirk ties to All Might without public scrutiny. Balancing hero training with home duties, she secured sixth in midterms. Guilt plagued her after opposing classmates’ reckless plan to rescue Bakugo, fearing it mirrored villainy; Ochaco Uraraka later mediated reconciliation, solidifying Tsuyu’s role as a stabilizing force. Interning under Selkie honed her rescue focus, culminating in solo villain confrontations to free her mentor. Collaborating with Ryukyu and Nejire Hado in the Shie Hassaikai raid, she adapted tactics to subdue Rikiya Katsukame. During Joint Training, her mucus masked allies’ scents to outmaneuver Jurota Shishida. The Final War saw her championing empathy over rigidity, convincing Himiko Toga to engage Ochaco despite prior conflicts. Post-war, she ranked 34th as a pro hero, prioritizing rescue operations in societal rebuilding. OVAs deepened her narrative: "Training of the Dead" highlighted sibling bonds, while "Make It! Do-or-Die Survival Training" showcased her rescue expertise, underscoring a heroism ethos transcending combat.