Yuri

Yuri is mature, shy, and has trouble with social interactions. She normally thinks carefully about what she says, but she is easily flustered and will impulsively blurt things out due to nervousness then repeatedly apologize for her outbursts. 

Yuri prefers to write using complex language and layer meaning under metaphors that require detailed interpretation. Yuri's writing and reading preferences greatly contrast with Natsuki's, which can create tension between them.