Nagi-Asu: A Lull in the Sea - Season 1 Episode 15 The Protector of Smiles
Overview: The day of the Tomoebi, a Hikari who hasn't aged from five years ago, appears in front of Miuna and Tsumugu. He has no memory of what happened since the Ofunehiki, but seems healthy and starts living at the Shiodome household.