Crux (クラックス) was started by Orca's software team after that company went bankrupt and was thrown out of its building. After doing Gyrodine, Crux ran into financial difficulties and would eventually go bankrupt as well. With such uncertainty, the chief programmer on Gyrodine and two others left for Toa Kikaku and started a software division which became Toaplan. Tatsuya Uemura (上村建也) was invited over but did not leave until after he finished working on Repulse. 
Research Methods: Online resources
- Gyrodine (Taito)
- Repulse (Sega)
- Taichi (unreleased)
- Development started at Orca but continued at Crux. There was a location test. 
According to Tatsuya Uemura, Crux went bankrupt during the development of Repulse.  However, we noticed some Crux staff worked on the following games (see also this image). Were these late Crux games? Were these early Whiteboard games? Did Takeshi Tozu have a company between Crux and Whiteboard? Were they in fact developed internally by Kyugo (a company that didn't seem to develop any games internally after this)?
- Airwolf (Kyugo)
- Flashgal (Sega)
- Legend (Sega)
- S.R.D. Mission (Taito)
- The names not circled on Legend in the above linked image turn up in the SG-1000 Wonder Boy ROM. Kamei, Maruyama, and Nakayama turn up as sound staff on various Whiteboard/Santos games.