Looks like the original web manga and the TV anime adaptation for Yayoiso’s ReLIFE series are ending during the same month. According to Yayoiso herself, she plans to release Chapter 211 of her hit manga on March 2018. As for the finale of the anime, they will release it as a 4-episode OVA, which will get its release on March 21, 2018. They also revealed a brand new PV for that upcoming OVA:
— 「ReLIFE」アニメ公式 (@ReLIFE_anime) December 22, 2017
The OVA will be released on both a Blu-ray and a DVD format. It will follow the events after the TV anime’s 13th episode. It will then conclude with the end of Arata’s ReLIFE experiment. They also revealed a brand new key visual for this upcoming finale OVA.
Aside from the 13-episode TV anime adaptation, ReLIFE also has a live-action movie adaptation.