I love the surprised Pikachu face at the end. Also I hope he doesn't end up with Mimiel and instead she learns about love through him getting together with Mei and her realizing that is love
idk, i feel at this point nothing fazes him anymore. the usual pattern is: mimiel says something crazy, the ren explains to her why it's dumb. when he hears something like that, i imagine his reaction is just "ah she 'learned' something again, now i gotta teach her about what it actually means" lmao