https://gleam.io/ZrGBg/sengoku-provi...senki-giveaway

A limited number of serial codes for a free 4* copy of the current dojo girl are going out to people who follow Nutaku's Twitter feed through the linked giveaway page. The codes can be redeemed by clicking on the in-game banner. And no, you can't use her as part of the evolution chain that goes up to 6*, apparently.