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.
I'm willing to participate in your 
joint practice as a trial member.
Ich bin bereit, als Probemitglied an eurem gemeinsamen Training teilzunehmen.
Puedo participar en la práctica en conjunto
Participaré en ese 
entrenamiento conjunto
Je veux bien assister à votre entraînement 
comme membre temporaire.
Potete considerarmi un membro
 in prova per quell'allenamento.
Eu aceito participar do seu treinamento
 coletivo como um possível membro.
Я готов участвовать в вашей совместной
тренировке как временный член.