Koi wo Suru Hi no Lingerie

Nazumi, a girl whose recent job has just closed shop, and is now between jobs. After her friend gets her a job at a lingerie store, some customers make fun of her chubbiness, but she is pulled out of the situation by Reo, a former middle school classmate of hers who was once a delinquent.

(Source: Kodansha, translated)