Sonoa gets drunk and ends up living at Tachibanakan. Yuu gets everyone to have a welcome party for Sonoa, so they meet by the riverside in appropriate outfits. Yuu has water guns waiting for them, and has everyone enter a "Water Gun Survival Game".
Wait, you couldn't have...
Moment, du hast doch nicht …
No puede ser, ¿tú…?
No puede ser. ¿Tú…?
Aspetta, non sarà...
Espera, você não...