Less than a year after taking an investment round, Loco Partners – owner of the Japan-focused Relux booking site – has sold the remaining shares to its backer.

Terms of the deal have not been disclosed.

In April 2016, the Tokyo-based startup that runs Relux, a membership-only accommodation service, secured 500 million yen (or about US$4.5 million) in funding from KDDI Open Innovation Fund, one of Japan’s three largest mobile carriers.

This followed 330 million yen (about $3.1 million) in Recruit Holdings-led funding in 2014.

Relux claims to have more than 650,000 members on the multi-language site (Japanese, Cantonese, English, Mandarin and Korean) and works in a similar way to Gilt Groupe-owned Voyage Privé, Secret Escapes and TripAdvisor-owned Jetsetter.

Some four out of five of Relux’s customers access the service via smartphone browsers.

The tactic enables the website to post discounted rates on upscale hotels, inns, and ryokans around Japan without sparking a price war with other sites thanks to the members-only veil.

The acquisition will see KDDI include a hotel booking service into its own mobile platform, known as AU – an integration that was first mooted at the time of the original KDDI investment last year.