Second season of Amanchu!.

Originally from a big city, Futaba Ooki spends most days cataloguing her life through pictures on her phone. Upon moving to a seaside town, she gazes out over the vast expanse of sea and quickly becomes captivated by its endless possibilities. Unbeknownst to Futaba, her quiet contemplation catches the attention of local diving enthusiast Hikari Kohinata. Finding herself in the same class as Futaba the next day, Hikari is drawn to her quiet and shy demeanor and affectionately nicknames her Teko, sparking a tender friendship. Struggling to adapt to the change of pace in her life, Futaba finds herself strung along by Hikari's vast energy and passion for diving. Together, they join the school diving club, led by their homeroom teacher Mato Katori. With Hikari by her side, Futaba works to earn her diving certification while experiencing new friendships and possibilities. [Written by MAL Rewrite]

In 2015, the Chaldea Security Organization draws on experts of both the magical and mundane fields to observe the future of mankind for possible extinction events. Humanity's survival seems assured for the next century—until the verdict suddenly changes, and now eradication of the species awaits at the end of 2016. The cause is unknown, but appears to be linked with the Japanese town of Fuyuki and the events of 2004 during the Fifth Holy Grail War. In response, Chaldea harnesses an experimental means of time travel, the Rayshift technology. With it, Ritsuka Fujimaru, a young man newly recruited to the organization, and the mysterious girl Mash Kyrielight, can travel back to 2004 and discover how to save humanity. A grand order to fight fate has been declared—an order to change the past and restore the future. [Written by MAL Rewrite]

Short centering on a "Lost Room" where you can find what was lost—or those who lost. This room, which belongs to no one, lies forgotten in a corner of Chaldea. (Source: ANN)