Prope

As part of Sega's "support program for independent game creators", Yuji Naka left Sega to start his own studio, along with ten Sonic Team members. It had a starting capital of ¥10 million, 10% of which came from Sega in exchange for the right of first refusal for publishing his studio's games. Prope was founded on May 23, 2006 and began operations one week later, on June 1.

Prope intended to create games with a graphical style that appealed to both children and adults, and to explore the possibilities of developing both 3D and 2D games. Naka joined Square Enix in January 2018, leaving the status of Prope uncertain. In March 2019, Naka confirmed that Prope had been reduced to a one-person company since the end of April 2017.

Naka released SHOT2048 under the Prope brand in December 2021, his first game following his departure from Square Enix back in April.

Previously, the studio had been consistently linked with a sequel to Nights into Dreams..., though Nights: Journey of Dreams was ultimately developed by Sega Studio USA. Naka has claimed in an interview that he presently has no intention to revisit any of his former Sega properties.

Prope's first two titles, the Wii rhythm game Let's Tap, and the WiiWare game Let's Catch, were both released in December 2008. Both games were published by Sega.

After a series of simplistic iOS games such as 10 Count Boxer and Fluffy Bear, under the iPrope label, Prope's next major game Ivy the Kiwi? was released in November 2009 exclusively for Windows Phone, with Microsoft publishing it. In April 2009, it was ported to WiiWare and DSiWare and published by Bandai Namco in Japan, Xseed Games in America and Rising Star Games in Europe as Prope's parent company Sega refused to publish the game and Bandai Namco decided not to publish the game outside Asia. In 2010, an expanded physical release (in contrast to a digital one) was released for Wii and Nintendo DS, featuring 50 levels (whereas the downloadable version featured 25) as well as original backgrounds and music for each level.

In 2011, Prope released Real Ski Jump, which, as of 2014, had been downloaded 4 million times.