In episode 12 of Nagi no Asu kara, Hikari confesses to Manaka. However, she just says "I don't understand", and then runs out.
What I don't understand is Manaka's reaction to Hikari's confession of love. In the latter half of the series, we learned that she actually did love Hikari when we finish the flashback of her talking with Tsumugu in the fishing boat. If she really felt that way about Hikari, then her reaction to his confession makes no sense to me.
I don't know if I'm just missing something, but this is the one major point I just don't understand from the story. I'd really appreciate if someone could explain it to me.