TOKYO (Reuters) - Activist investor Oasis Management has called for governance overhaul at scandal-hit Ain Holdings, Japan's largest drug store chain, in its latest activist campaign targeting a Japanese company.

Oasis said there was no independent oversight of management at Ain and has proposed the appointment of four new outside directors, a new compensation plan for outside directors, and the dismissal of two incumbent directors.

Ain had disclosed earlier it received Oasis' shareholder proposals in early June and responded on June 26 saying the company believed their board had sufficient independent oversight and that Oasis' proposed outside director compensation plan would leave it unable to respond flexibly to the external market environment.

An Ain spokesperson said on Friday the company was in the process of studying Oasis' campaign announcement.

In 2023, a director from Ain and another from an Ain subsidiary were prosecuted for mishandling documents related to a public contract bid. Both were found guilty in April 2024.

Ain shares fell 3.5% on Friday morning, compared with a 1% gain on the benchmark Nikkei index.

Hong Kong-based Oasis launched in April a campaign aimed at cosmetics and skincare firm Kao, demanding it redefine its brand portfolio and improve marketing.

(Reporting by Anton Bridge; Editing by Christopher Cushing and Muralikumar Anantharaman)