The second movie, titled Midsummer's Equation (真夏の方程式, Manatsu no hōteishiki), premiered in both Japan and Hong Kong on June 29, 2013.

Kaoru Utsumi, a rookie detective who has just been reassigned to the criminal division, finds the investigation of her first murder case stalled by seemingly-supernatural phenomena surrounding the event.

Kusanagi, however, reveals to Utsumi that he was only able to solve the cases thanks to his college friend, Teito University professor Manabu Yukawa.

Yukawa is a tall, handsome, brilliant but eccentric scientist who is interested in nothing but physics, while Utsumi is a hot-blooded detective with a strong sense of justice.

[1][2] An adventure game based on the series was developed by Tomcat System and published by D3Publisher for Nintendo DS on October 16, 2008.