Senran Kagura: Estival Versus has sold around 100,000 copies in Japan, according to series producer Kenichiro Takaki. It was released on March 15th.
Takaki adds that the game saw a sell-through of 80-90%, and that the download version of the game sold 10,000 units.
The previous Senran Kagura “Versus” game, Senran Kagura: Shinovi Versus, sold 120,000 copies in its first five days, including download sales.
Senran Kagura: Estival Versus was released for PlayStation Vita and PlayStation 4.
Update: Following the release of official sales data by Media Create, it appears that the game definitely did not sell 100,000 copies in its launch week alone. The game sold 74,795 copies at retail at launch, and if one were to combine that with the download sales numbers, it brings us to 84,895–still nowhere near 100k.