It is possible this specific series was deleted (common on fan sites) or it is a typo for a more famous work like:
Through a supernatural or sci-fi occurrence, the protagonist undergoes Tainai Kaiki (regression to the womb). Instead of just traveling back in time, he literally returns to a fetal state within his childhood friend's body. 🔍 Key Characteristics
" (translated roughly as Regression into the Womb: I, a NEET, Return Inside the Womb of the Childhood Friend I Mocked ). 📖 Story Premise -Doujindesu.TV--Tainai-Kaiki--Neet-no-Ore-wa-Ba...
Look for tags like: Horror , Psychological , Seinen , Body Horror , Parasites , Comedy .
The search fragment reveals a specific hunger in the manga community: It is possible this specific series was deleted
If you find the series on Doujindesu.TV and love it, search for the author's name on Pixiv Fanbox or Fantia. Most Tainai Kaiki artists are independent doujin creators who sell digital copies for 500 Yen ($3.50). Buying the original is the only way to get a sequel.
Our protagonist is Tanaka (a generic surname), a 28-year-old NEET who has lived in his parents’ basement for five years. He spends his days binge-eating snacks, playing gacha games, and reading isekai fantasy. 📖 Story Premise Look for tags like: Horror
Based on typical Doujindesu.TV hosting patterns, the art for this series would be:
When searching on Doujindesu.TV, use the Japanese characters: ニートの俺は体内回帰にハマりたくない (NEET no Ore wa Tainai Kaiki ni Hamaritakunai). If nothing appears, the series may have been lost to time—or it is waiting to be translated by a fan just like you.