The Iwatobi Swim Club needs one more member before it can participate in relays.  Nagisa has set his sights on his classmate Rei, who is a member of the track team.  Despite Rei's refusal to join, but Nagisa appears intent on recruiting Rei into the swim club.
How do you know?
Woher weißt du das?
¿Cómo lo sabes?
¿Cómo sabes todo eso?
Comment le sais-tu ?
Come lo sai?
Como sabe de tudo isso?
Откуда ты знаешь?