I really have mixed feelings for this one. I am actually a fan of animes with this kind of themes + I've watched the two seasons of kakegurui itself. Mary Saotome is a well-written character though she isn't my favourite of this anime. The art of this ONA isn't up to expectations as the only decent looking character is Mary. The OPs and EDs were good though. For enjoyment I will give it a 7. There were some twists and cute scenes that can match up to the main story itself. So yep XD a 7. If you like MarySaotome a lot and you want to watch animes under this genre, you should watch it.