Complex sentence: Yui wins a contest to become the symbol character of the Kitasanriku Railroad, and when Yui's older brother Hiroshi takes a job at the local tourism bureau and uploads videos of his sister on the town website, train otaku begin flooding the town.
Split into simpler sentences: Yui wins a contest to become the symbol character of the Kitasanriku Railroad. When Yui's older brother Hiroshi takes a job at the local tourism bureau and uploads videos of his sister on the town website, train otaku begin flooding the town.