Shū ni Ichido Classmate o Kau Hanashi: Futari no Jikan, Iiwake no Go Sen-en (週に一度クラスメイトを買う話 ～ふたりの時間、言い訳の五千円～) is a Japanese light novel series written by Usa Haneda and illustrated by U35.

It originally began serialization on Kadokawa's user-generated novel publishing website Kakuyomu in February 2020.

A manga adaptation by Migihara began serialization in Akita Shoten's Young Champion Retsu magazine in June 2024.

Initially serialized as a web novel on Kakuyomu since February 2020, the series began publication by Fujimi Shobo under their Fujimi Fantasia Bunko imprint in February 2023 after winning a Special Award at the 7th Kakuyomu Web Novel contest.

[3] A manga adaptation illustrated by Migihara began serialization in Akita Shoten's Young Champion Retsu magazine in June 2024, with plans to move the series to the company's Young Champion Web service in the future.