sorry to be the bearer of bad news, but you don't have anything going for you. despite his introverted otaku-ness, densha did help the pretty lady. in this scenario it was the pretty lade who stood up and helped you, so then maybe you had the opportunity of being the thankful one and sending the gift... EXCEPT you didn't ask nor did she offer her address, so it might come off stalker-ish. maybe its customery in japan, but think about your own circumstances outside independently of densha. who sends a gift for a free ride?

you are already doubtful and not wanting to waste money. think about why you doubt. i hate to be the bearer of bad news, but you are trying so hard to compare your situation to densha that you might just end up letting yourself down.

IF you're just gonna ignore me anyways, heres this on a tip for a gift: if it was a long trip, then it cost her gas n time... so send her a card with a gift card to reimburse for her troubles... she seems to like shopping.