A decayed dragon contractor (Volume 1-2 is the latest issue)

the publisher:
Author: Midori Wataru
Size: 128mm x 182mm
Number of books: 2
Language: Japanese
Category: Girl manga, manga
Latest publication date: 2023-01-16

Synopsis:
A 16 -year -old boy, Yao, inherited the antique shop left by his grandmother.
As a result of his care, he has been treated with his soul, and among the antiques, "Monono Coin"
He also worked on the work of a villain to purify the "Koware", which had been covered by darkness and attacked people in various ways.
In the past, "antique goods with a soul soul" were attacked,
He continued to follow the whereabouts of Koware who hit her sister to wake up her sister, Meyrin, who was 12 years old and continued to sleep.
The request of the evil exorcist is entered under him.
This time, he was enthusiastic about waking up his sister, but he was attacked by the kware and died.
It was a huge dragon with old power that helped him, who was desperate to die without anything!
What is the identity of this dragon ...?
And what the encounter between these two guide me ...!?