It is possible! I can't give definitive steps to getting it, but it's based on how close you are with him, based on choices in previous days.
Yep, I've so far found two different endings based on max/min reputation with him but they don't change too much, just how you react when you two go to the room. I wouldn't be surprised if it had a bigger impact on later days though.
EDIT: so I messed around with all possible heart points when getting to the end, it seems like getting the hug at the sunscreen part requires you to have all 4 previous heart points with him. Also it seems there's only the two endings, one where you have 5 heart points at the very end and one for any less than that... Maybe I'm wrong and there's another ending for maybe high heart points and low friend points or something like that, maybe it's just the two and the 'several' is a translation error... If you want to see what actions to take to get max heart points, there's a doc linked a few comment chains up.