Dempsey’s national team-mate George Turner did not feature for Scotland during his year in Japan playing for Kobelco Kobe Steelers, only returning to the national fold when he joined English side Harlequins last summer.
It is understood terms had largely been agreed on a new contract for Dempsey to remain at Scotstoun beyond this season.
However, the length of the deal proved a sticking point in negotiations and Dempsey, who turns 32 next month, has decided to take up the lucrative offer to play his rugby in Japan.
The identity of Dempsey’s new team has yet to be announced.
He was a key figure in Glasgow’s United Rugby Championship title win in 2024 and has become Scotland’s undisputed first-choice number eight since making the switch from his native Australia – for whom he won 14 caps – in 2022.
Dempsey is one of a number of high-profile departures from the Warriors squad this summer, with Huw Jones and Adam Hastings both moving to France to join Toulon and Montpellier respectively.
