"Senjitsu Sukutte Itadaita Dragon desu": Oshikakenyoubou shitekita Bishoujo to, Inkyo shita Moto S-Rank Ossan Boukensha ni Yoru Henkyou Slow Life

"Retired S-Rank Adventurer's Slow Life with a Black Dragon"
Lark, a retired S-rank adventurer, was introduced to a "wonderful village" where he could peacefully spend his later years by a friend. However, upon arrival, he finds himself in a deserted village with no one around.
Through an unexpected turn of events, Lark ends up rescuing a Black Dragon who was trapped in a snare. The following day, a black-haired beautiful girl appears before him.
"I am Dia, the dragon you saved the other day! I came to thank you, so please accept my gratitude!" This marks the beginning of Lark's somewhat unconventional and noisy slow life, as he finds himself entwined with a Black Dragon and the adventure that ensues.