[Yosomono] Let's Defeat a Dragon Together! (COMIC AUN 2021-02) [Thennos Scans]

A bespectacled older brother and his petite, twintailed sister trade quips about a popular co-op RPG and an embarrassing exercise ring, setting the stage for an intimate sibling rendezvous in her bedroom. When the girl straddles him in her gym bloomers to 'train together,' he introduces her to a pleasure she never expected from her beloved brother. Drawn by Yosomono for COMIC AUN and presented by Thennos Scans, the story balances playful sibling banter with escalating intimacy and first-time discovery.