Years after the war, Japan’s top pro heroes are finally enjoying a hard-earned peace—until Denki Kaminari drops a bombshell on his closest friends: he has a twin sister no one knew existed. Returning home after years living across the country, Y/N Kaminari is quickly welcomed into the former Class 1-A’s chaotic circle. Everyone is shocked by Denki’s long-kept secret, but no one is more affected than Eijiro Kirishima, who finds himself instantly captivated by her quiet warmth and unwavering kindness. As friendship slowly blossoms into something deeper, Kirishima must navigate an overprotective twin brother, relentless teasing from their friends, and the possibility that the best thing to happen to him was the secret Denki never meant to keep.