Three male classmates set off on a hot spring vacation with a firm pact to keep things completely sex‑free. But the vow quickly unravels as each boy becomes entangled in secret encounters—often while trying to hide under the same covers or in adjacent rooms. The central conflict revolves around the constant risk of exposure: any muffled noise, suspicious movement, or awkward timing could reveal what is really going on. The narrative follows a spiraling chain of near‑misses and escalating complications, with the characters repeatedly forced to improvise excuses while their hidden activities threaten to break into the open. Over its long run, the manga builds its comedy and tension around the group’s increasingly desperate attempts to maintain secrecy, exploring the dynamics among the three friends and the various romantic or sexual entanglements that develop during and after the trip. The hot spring vacation serves as the catalyst, but the story extends well beyond it, continuing the pattern of concealed liaisons and the looming fear that one day everyone will indeed find out.