Time limited skins are scummy as well.
Release skins like Neko Kurumi and Maid Kotori for like 20$, no time limit.
At the same time have skins gacha and some normal missions where you can get a token to roll with maybe every 2 days (and like a bonus token in store with every new event that you can buy with currency). The drop rate of skins is still low, but you can hope to get something that way one day. If you give up on gacha, you can at any time purchase the skin with money, and it gets removed from the gacha for you so you don't get annoyed with sudden useless dupe few days later. Maybe add a bunch of non-full screen gacha only skins with higher drop rate.
That way the skins would still be very hard to get for free, but players have at least some chance to eventually score one, and the devs don't look like supreme jews like during Kurumi "event"