Kimi-iro, Boku-iro

Take every beloved character from KonoSuba, Re:Zero, Overlord, and Saga of Tanya the Evil, throw them into a school together, and then give that whole vibe a song — that's basically what Kimi-iro, Boku-iro is. It's a music video featuring a duet by Konomi Suzuki and Kashitaro Ito, originally used as the ending theme for Isekai Quartet 3, and it carries way more warmth than you'd expect from something under four minutes. The video itself doesn't try to tell a big story. Instead, it leans into the school setting that Isekai Quartet built, showing these characters just hanging out — goofing around in classrooms, walking hallways, being friends in a way that shouldn't work given how different their home series are. But it does work, and the song ties it all together with this gentle, nostalgic energy. Konomi Suzuki's voice paired with Kashitaro Ito hits a sweet spot between upbeat and bittersweet, like the feeling of a school year ending. If you liked Isekai Quartet and want one more little piece of that crossover world, this is a nice way to sit with it for a few more minutes. If you're a fan of either vocalist, it's worth checking out just for the performance. It's not trying to be anything grand — just a youthful, lighthearted tribute to characters people care about, sharing a space they were never supposed to share. Sometimes that's enough.