Atsumeru is the bookshelf server for people whose manga and comic collection lives in CBZ files scattered across drives: point it at the folders and it becomes a tidy library you can read from anywhere. Series organize themselves into auto categories, custom categories, and metacategories, and metadata edits are painless, with automatic import from ComicInfo.xml and book_info.json files and parsing from supported catalogs when you want richer records. Reading happens in native apps for Windows, Linux, Mac, and Android, or in the built-in WebUI, and two-way history synchronization keeps your place when you move from desk to phone. Whole series download inside supported apps for offline reading, which turns a commute into a chapter backlog clearing session. Multiple users get separate histories and powerful access controls, so a household shares one server without sharing reading progress or seeing each other's shelves. A documented REST API with Swagger on board covers automation and custom clients. The server runs as a single jar or a Docker container on port 31337, small enough for the spare machine already holding the files. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.