The main thing I still don't get is how she forgot, they mentioned in an earlier chapter that they were still communicating the first 3-4 years after Hina moved through mail and phone calls, than Hina just, stopped. just like that, like did she just up and forget everything about Akira one day? She just wake up one day and go "did I have a fiancé I've been talking to the last 4 years and even called for a few hours last night? No definitely not, Never knew another girl in my life." or something?