| Sekai to Sekai no Mannaka de | |
|---|---|
 Cover art, featuring (clockwise from the bottom left): Haruka, Minori, Kokoro, and Aira. | |
| Developer(s) | Lump of Sugar |
| Publisher(s) | Lump of Sugar |
| Platform(s) | Windows |
| Release |
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| Genre(s) | Eroge, Visual novel, Bishōjo Game |
| Mode(s) | Single-player |
Sekai to Sekai no Mannaka de (世界と世界の真ん中で), subtitled Celestial Globe of Your Heart, and sometimes abbreviated as Sekachu (セカチュー), is a Japanese adult visual novel developed by Lump of Sugar and released on January 31, 2014 for Windows PCs. The story of Sekachu begins with Renri Ōmi's younger sister Kokoro being discharged from the hospital. When he and his friends are cleaning out the Erdõs dormitory, they find various clues which guide them to a mysterious object.
The gameplay in Sekachu follows a branching plot line which offers pre-determined scenarios with courses of interaction, and focuses on the appeal of the female main characters by the player character. The game was a commercial success at the time of its release, however, sales declined later on that year.