This chapter got...surprsingly serious. Seeing Rei's mask almost crack was fascinating. It seems that she only keeps up her antics because she doesn't want to be serious, and thus vulnerable. Including her past life she may have had many experiences where her love would never be reciprocated, and that's always painful. Especially if revealing that love could cause the friendship to end and even social isolation. But Claire is....different. Claire seriously backed up Rei in this chapter and seems to at least see her as a true friend, though she may not be admitting it yet.
It's an interesting case as well of what relationship both parties are comfortable with. If Claire absolutely isn't attracted to women, they might both be fine with being best friends as time goes on, but I'm concerned about whether Rei would be truly comfortable with that. If anyone was facing this situation irl, my advice would probably be to just settle for a friendship with some distance and find someone who would love you back. Unrequited love is painful, especially long term, and staying close to your love will just drag out that pain for longer.