Why Does Nobody Remember Me in This World?

Why Does Nobody Remember Me in This World? (なぜ僕の世界を誰も覚えていないのか？) is a Japanese light novel series written by Kei Sazane with illustrations by Neco. It was published under Media Factory's MF Bunko J imprint from July 2017 to August 2020. A manga adaptation illustrated by Arikan began serialization in Media Factory's Monthly Comic Alive manga magazine in February 2018. An anime television series adaptation produced by Project No.9 premiered in July 2024.

Plot
A war between five races for supremacy on Earth is won by humanity, led by the hero Sid. Suddenly, history gets overwritten so that Sid never existed, leading to humanity losing and becoming subjugated by dragons and demons. All of this is witnessed by a boy named Kai, who is mysteriously unaffected by the alterations. In this new world, Kai finds that he never existed previously, so no one knows him. After meeting a mysterious girl named Rinne, Kai is inspired to become the hero himself and free humanity.

Characters

 * Kai Sakura Vento (甲斐サクラヴェント)

A soldier of the Urza Federation.
 * Rinne (リンネ)

A girl of an unknown non-demon race whom Kai rescues. She is brought to the human resistance camp where she helps them in the fight against the demons.
 * Jeanne (ジャンヌ)

A high-ranking soldier of the Urza Federation Army and Kai's close childhood friend from his world. In the alternate world, she leads the human resistance masquerading as a man, with her true identity as a woman only known to a few close aides.
 * Ashuran (アシュラン)

A soldier and Kai's colleague of the Urza Federation Army. In the alternate world, he is a member of the human resistance force.
 * Saki (サキ)

A soldier and Kai's colleague in the Urza Federation Army. In the alternate world, she is a member of the human resistance force.
 * Farin (花琳)

Jeanne's close aide and bodyguard.
 * Reiren (レーレーン)

Manga
A manga adaptation illustrated by Arikan began serialization in Media Factory's Monthly Comic Alive manga magazine on February 27, 2018. It has been collected in eleven volumes as of April 2024. The manga adaptation is published digitally in English on Kadokawa Corporation's BookWalker website.

Anime
In July 2023, during the MF Bunko J Summer School Festival 2023 event, an anime television series adaptation was announced. It is produced by Project No.9 and directed by Tatsuma Minamikawa, with scripts written by Satoru Sugizawa, and characters designed by Hiromi Kato. While the anime received an advance screening on June 16, 2024 at the Grand Cinema Sunshine in Ikebukuro, Tokyo, it later officially premiered on July 13, 2024, on Tokyo MX and other networks. The opening theme song is "Sekai Rinne" (セカイ輪廻) performed by Unlucky Morpheus, while the multiple ending theme songs are performed in the following: the first is "Togirenaide" (とぎれないで) performed by Susu, the second is "Ai, Amnesia" (アイ、アムネジア) performed by Urbangarde, and the third is "Umbra" performed by Elfensjón. Crunchyroll licensed the series. Medialink licensed the series in East, Southeast Asia and Oceania (except Australia and New Zealand) for streaming on Ani-One Asia's YouTube channel.

Reception
By July 2023, the series had over 700,000 copies in circulation.