Leaf is a Japanese
visual novel studio under the publisher
Aquaplus, and has offices in Yodogawa-ku, Osaka, and Tokyo. It and its competitor
Key (to which it is often compared) are two of the most popular and successful dedicated visual novel studios operating today. It was launched out of obscurity by its early release
To Heart. Leaf used the
XviD video codec in several games:
Aruru to Asobo!!,
Tears to Tiara,
Kusari, and
ToHeart2 X Rated. Since XviD is free software, released under the
GPL, Leaf was forced to release the source code to those games under the same license. One still required the game data to actually play the games with the source code. In addition, a free software engine called xlvns was developed soon after Leaf released its first three visual novels. Characters from
Utawarerumono,
Tears to Tiara,
To Heart, and
Kizuato are playable in , a fighting game developed by Aquaplus featuring characters from various Leaf games.