Hmm, it's hard to tell if she just has a hard time denying things or saying no because she's meek, or if she just genuinely enjoys being ordered around/likes helping people.
That ending though. Hmm, yes, a whole lot indeed. I think his old man has caught on to what happened.
Hmmm ... trying to process just what went on here. Female protag-kun can't seem to say "no". Male protag-kun pushed her buttons (figuratively speaking), seeking to determine her cut-off point. They end up at the very least in a mostly physical relationship (even Manager-san suspects something by the close).
*crickets chirping*
I'll allow it ... let's move on.
EDIT: looking at this again, Asazato-san is older than Tooru-kun. Conclusion: MC got himself a Sexy Onee-san girlfriend ..... Lucky Bastard.