Valis (ヴァリス Varisu?) is a Japanese platform game series developed by Telenet Japan. The original game was developed in 1986 for the MSX, and its popularity has spanned four sequels, a spin-off, and remakes across several platforms, notably the TurboGrafx-16 and Sega Mega Drive until the early 1990s, when it was quietly retired. The Mega Drive/Genesis entries were all published in North America by Renovation Products. Later, Telenet sold the series' rights to a company known as Eants, which re-tooled the series as hentai games[1] after Telenet shut down in 2007. The series has formed two Mobile Phone games released by Bandai Namco Games in Japan and a manga by Kill Time Communications. The Valis games (as they were known in America) tell the story of Yūko Asō (麻生 優子 Asō Yūko?), a schoolgirl in late 1980s Japan who is fated to protect three different realms – our own Earth, the land of spirits, and Vecanti (ヴェカンティ Vekanti?), the Dream World – by wielding a mystical sword known as Valis.

Vapor Trail: Hyper Offense Formation, known in Japan as Kuhga – Operation Code Vapor Trail (空牙 – Operation Code Vapor Trail?) and usually simply referred to as Vapor Trail, is a 1989 shoot 'em up arcade game developed and published by Data East. Vapor Trail was followed by Wolf Fang and Skull Fang Kuhga Gaiden.

Virtua Fighter 2 (Japanese: バーチャファイター2, Hepburn: Bācha Faitā Tsū?) is a fighting game developed by Sega. It is the sequel to Virtua Fighter and the second game in the Virtua Fighter series. It was created by the Sega's Yu Suzuki-headed AM2 and was released in the arcade in 1994. It was subsequently ported to the Sega Saturn in 1995 and Microsoft Windows in 1997. In 1996, a super deformed version of the game, Virtua Fighter Kids, arrived in arcades, ported to the Sega Saturn in the same year. It was also ported to the Mega Drive/Genesis in 1996, but because the hardware couldn't handle the complex visuals of the arcade version, it was re-made as a 2D fighter. In addition, Virtua Fighter 2 was converted for the PlayStation 2 in 2004 as part of Sega's Ages 2500 series in Japan. The Mega Drive/Genesis port was re-released on the PS2 and PSP in 2006 as part of Sega Genesis Collection, on the Virtual Console for the Wii on March 20, 2007 (Japan) and April 16, 2007 (North America), and for iOS on January 20, 2011. VF2 was known for breakthrough graphics at the time. It used Sega's Model 2 arcade hardware to run the game at 60 frames per second at a high resolution with no slowdown. The Saturn version was also extremely impressive for its time, especially given the system's 3D programming difficulties. It became a huge hit in Japan and sold relatively well in other markets, notably the UK, where The Prince (Hatim Habashi) was crowned by Sega Europe as the Official UK Virtua Fighter 2 Champion. The arena size could be adjusted up to a very small platform or all the way to 82 meters, which in the genre is considered very large; this is the only game in the series—other than Virtua Fighter Remix—that could have such size adjustments. The physical energy meter could also be adjusted to infinity as well, giving you the advantage when beating opponents in the game or practicing moves against the computer player. Incidentally, players discovered that adjusting the arena to a smaller size and giving the characters infinite health could lead to mock sumo matches, wherein victory is achieved by knocking the other player out of the ring.