So I managed to collect all characters’ Hope Shards (by talking to them and giving them presents ^^;)
Doesn’t seem to give any ultimate reward, but I did get 2 silver trophies (I have decided not to check trophy lists of games that I’m playing, so these are nice surprises ^^).
It may seem I’m done with relationships but in Island Mode apparently there is another way to increase relationship (with different metric) and that is by using the ‘date tickets’ obtained from successfully completing missions. Not sure what happens when you max a relationship with this method… Gotta test it out… on Chiaki first, of course :p
Edit: Raised Chiaki to max but it doesn’t seem to do anything. I guess it’s just to accelerate getting Hope Shards (which I have gotten all)
Based on the minimum number of tickets required to bring Chiaki to max, I don’t think it’s possible to bring everyone up in one playthrough. Not only that, it doesn’t seem to carry over to the next playthrough too…