"I bought an old slave with one coin (and got change back)." Tanya, a lonely girl, buys a slave, William, for one coin. Tanya wants to be family, but they're "master" and "slave." It's the incongruously woven daily life of two people with different ages and social standings.
Moshimo Kubiwa Ga Hazuseta Naraba Chapter 19
Moshimo Kubiwa Ga Hazuseta Naraba Chapter 20