Second part of Douluo Dalu.

Three devil girls Aira, Shima, and Hana live in the human world. Leading a dazzling school life with efforts and friendships, they aim to be idols. It's a heart-bumping anime climbing that stairs... Not! They don't know the answer to "What is Idol?" and weaver in the road to becoming an idol with trials and errors. Rocket-sensei will kindly (and sometimes strictly) lead them to become real idols in an unique way... for sure. (Source: MAL News)

A short anime based on Manga de Wakaru! Fate/Grand Order by Riyo. Aired during Fate Project Year End 2018, and is also available on YouTube.