Seems that virtually all of Takumi's friends are Men Of Culture in that they consider him (1) a hero (2) a lucky bastard (3) WHY NOT BOTH?, for scoring an older woman as his girlfriend (page 16).
Funny you say that, there's a manga by the same author called Ookumo-chan Flashback where there's a manga called Unconfirmed Girlfriend X and it's basically Mysterious Girlfriend X, but instead of scissors she uses a wrench.
I find the title to be rather interesting.
Hmm, so his friend pressuring him into proving that he had a girlfriend provided our heroine here the perfect chance to go for him, eh? That's nice.
I quite like the ending though. Despite her being a stalker of sorts, he still came to like her enough that he wants to 'make the lie I(he) told my(his) friend', so that's nice! And hey, she even has his mother's approval!
Whenever I'm asked how we met I could never come up with a believable story.
Tell them you were walking down the street not paying attention because you were too busy with your phone when you crash landed onto a wonderful pair of tits.
Oh-Kay ... so Yukie's been 'stalking' Takumi since they had a "Crash Into Hello" encounter, she recognizes his attraction towards (a-hem) tig ol' biddies, she's got his Mom's Approval, and she happily Om-Nom-Nom'ed his virginity faster that Pac-Man could move.
Perhaps we should volunteer this as a tag: "Entrapment".