So…I’m not entirely sure if I’ve figured out what’s going on here.
It LOOKS like Hifumi went panty-thieving and managed to nab Koharu and Azusa’s underwear, with the implication that Hifumi escaped unscathed because she wasn’t wearing any. Thing is, I’d expect Hifumi to be the one wearing Peroro-themed clothing instead of Azusa, so I’m kinda unsure if I’m reading this image right.