For the people who can't read Japanese (and don't know any better) but are tagging this anyway: that is not Rin. That is the daughter of the owner of one of the places Shirou works part time.
An update: Okay, "Hotaruzuka Otoko" is not the correct tag, either. Character tags should always be in given name - family name order (should be obvious if you look at the already-defined character tags that have been applied to this gallery, including the obviously completely incorrect tag that is still going strong after all these years while an obviously correct one is still languishing with barely any power, because people are dumb), therefore the correct tag would be "Otoko Hotaruzuka." ...Which I can't tag, because for some reason the "misc" namespace lets you make up some extra tags that haven't been defined but not necessarily all the time. Because systems that make sense are for losers, I guess.