Sony Corp America will buy a $400 million stake in Bilibili, a Nasdaq-listed Chinese video platform popular with millennials for its animation and gaming content.

The deal, announced Thursday, will give Sony a 4.98% holding in the Shanghai-based company, making it the fourth-largest outside shareholder behind Alibaba Group Holding, Tencent Holdings and Loyal Valley Capital.

"Sony believes China is a key strategic region in the entertainment business, and this investment in Bilibili is in line with Sony's strategy," the Japanese company said in a statement.

Bilibili Chairman and CEO Chen Rui said in a statement that the tie-up with Sony will "further align our goals to bring best-in-class content offerings and services to our users, as we increase our domestic stronghold in animation and mobile games."

Starting out as an animation site popular among teenagers, Bilibili is expanding into other areas such as documentary, esports, and music videos, attracting more than 130 million monthly active users.

Bilibili positions itself as a community for China's Generation Z, which it defines as those born between 1990 and 2009.

Daily time spent per active user on the platform's mobile app averaged about 80.1 minutes in 2019, Bilibili said in its annual report. The site had 130.3 million average monthly users in the fourth quarter.

Previously, Bilibili and Sony Music Entertainment had announced a partnership which gives users of the streaming platform access to music videos in Sony's library.