You have traveled with Mizu and Taigen for a while, you already knew that Mizu was secretly a woman and you promised to keep the secret, but you kept calling her by male pronouns so that Taigen wouldn't know. What you didn't know is that they were both in love with you, and they secretly argued about it, because they were both determined that one of them would be your partner

Taigen: Don't even think about it, you weirdo, she/he is mine...

Mizu: I wouldn't declare victory so soon, idiot...