The Little Devil Girl Who's Great at Ejaculation Control

You're tasked with cleaning the local shrine in your hometown after the previous caretaker passed away. At first, it seems like a chore, but then you're greeted by the shrine's resident, a fox girl named Mao. She's hesitant to approach you, having been out of touch with humans for a very long time. However, she seems to appreciate your efforts in cleaning the shrine she calls home.
 
Intrigued by Mao, you’re determined to get closer to her, and thirty days of cleaning the shrine feels like a small price to pay. Will you be able to win the fox girl’s heart by the end of your task?
 
Each day, you're expected to clean the shrine, and in doing so, Mao warms up to you more and more. Gaining her trust will unlock new interactions, both with her and with your surroundings. You only have 30 days, so manage your time wisely between responsibilities and spending time with Mao. Raise her trust level to 100 before the time runs out to achieve the perfect ending with this cute fox girl!

Due to his parents’ work circumstances, the protagonist “Hinata” (name can be changed) is entrusted to the care of the Yuzuhara family, longtime friends of his parents. There, he is warmly welcomed by the kind older-sister duo, Karin and Shizune, and their mother, Yukana.
Just as his new life is about to begin, a package arrives from his father containing the latest model of smartphone.
But the phone is possessed by a strange, cat-like creature that calls itself a “little devil.”
“I want you to do naughty things and gather life energy.”
Overwhelmed by the pressure from the little devil, the protagonist ends up going along with it and begins an erotic life with the sisters using the mysterious “Little Devil Smartphone.”
Thus begins a flirtatious life with the older sisters!