Osamake: Romcom Where The Childhood Friend Won't Lose (幼なじみが絶対に負けないラブコメ, Osananajimi ga Zettai ni Makenai Rabu Kome, "A Romantic Comedy Where the Childhood Friend Absolutely Will Not Lose"), abbreviated as Osamake (おさまけ), is a Japanese romantic comedy light novel series written by Shūichi Nimaru and illustrated by Ui Shigure.

An anime television series adaptation by Doga Kobo aired from April to June 2021.

He lives next door to his childhood friend Kuroha Shida, a small and cute Onee-san type of girl with an outgoing character.

Written by Shūichi Nimaru and illustrated by Ui Shigure, Osamake was published by ASCII Media Works, under its Dengeki Bunko, in thirteen volumes, released from June 8, 2019, to February 7, 2025.

A manga adaptation by Ryō Itō began serialization in Media Factory's Monthly Comic Alive in November 2019, with six tankōbon volumes were published so far.

A spin-off manga series illustrated by Mutsumi Aoki titled Osananajimi ga Zettai ni Makenai Love Come: Otonari no Yon-shimai ga Zettai ni Honobono suru Nichijō ("Daily Lives Where the Four-Sister Neighbour Absolutely Will Make You Warm") began serialization in Media Factory's Monthly Comic Alive on January 27, 2021.

", while Inori Minase and Ayane Sakura performed the series' ending theme song "Senryakuteki de Yosō Funō na Love Comedy no Ending Tema Kyoku" (lit.