According to the LORE of the series of light novels written by Tappei Nagatsuki and illustrated by Shinichirou Ootsuka, Re: Zero Kara Hajimeru Isekai Seikatsu (Re: Zero - Starting Life in Another World), the character's birthday is celebrated Subaru Natsuka, who is the protagonist of history. The official Twitter account shared an update that pointed out that the Re: Zero - Lost in Memories videogame celebrated the occasion. «Today is Subaru Natsuki's birthday! And from now on we will celebrate year with year within the video game! But it seems that it does not believe us, how bad you are Barusu! "He wrote the account.
Different Twitter accounts also shared a series of illustrations to commemorate the character's birthday, mainly through the hashtag # ナ ツ キスバル 生誕 祭 2021.
About Re: Zero Kara Hajimeru Isekai Seikatsu
Tappei Nagatsuki began the publication of light novels in April 2012 on the Shoussuka Ni Narou website, and later the Kadokawa publisher began its publication on paper with illustrations of Shinichirou Otsuka in January 2014. The publisher published the twenty-fourth volume the past September 25, followed by the twenty-fifth on December 25 in Japan.
The first season of animated adaptation was 25 episodes and was released in April 2016. A second season had a total of 25 episodes, however, its transmission was divided into two part of thirteen and twelve episodes, respectively. The first part was issued during the summer season-2020 (July-September), while the second part was issued during the winter season-2021 (January-March).