@LANthus
Marisa is only the lead in pairings with her and Reimu because she loves teasing the shrine maiden and getting that ice cold facade to crack despite her best efforts to play it cool. And books that she's stealing^H^H^H finding.
@Nine exactly.
@LANthus
My headcanon is that Marisa is a huge tease and a flirt but otherwise isn't especially interested in relationships because she doesn't feel it's safe to be that vulnerable, which is why she's so flummoxed and thrown off balance by Alice approaching her romantically. Poor girl doesn't believe she's worth affection even though Alice knows she is ;w;
@LANthus
Oh heck, and with as powerful as Alice is there's no way Marisa wouldn't have "popped round for a visit on the way past" and decided to "borrow a book or two" while Alice wasn't there... So probably saw that room with the dolls and noped the heck out. Alice does come on rather strong I guess. Must be nervousness. She does spend an AWFUL lot of time alone.