Glossary Entry : Shounen-Ai
Abstract:   Material including male-male romantic attraction.
Shounen-ai is a Japanese term for `boy love'. Yaoi has a more complex derivation and is probably an acronym. The translation being "Yama nashi, Ochi Nashi, Imu Nashi", or `no peak, no point, no meaning'. The other possibility being the rather more informal "Yamete Kudasai, Oshiri ga Itai", which means "please stop, my ass hurts". In any case both of the genre's are depictions of male-male romantic pairing intended for consumption by a female audience. As such it may seen a very exotic and specialized genre to the western fan, and indeed these genres are far less common than most.
The Japanese usage of the terms is not entirely clear to me, with some suggestions being that both words are used by different groups to describe the same wide genre. Likewise it has been said that yaoi refers only to doujinshi (fan manga). However many western fans use the terms to separate the genre into two. Shounen-ai is used for those stories where the focus is on the character drama of the relationship. While Yaoi is used for more explicit, sexually focused, material.
The appeal of shounen-ai stories may not be obvious to many. It has the superficial benefit of allowing bishounen (pretty boys) to be romantic, sensitive and intimate with each other. It also has the property of allowing shoujo concerns with character and interaction to be examined using male subjects and male `modes'. And, finally, it allows stories of forbidden, destructive and taboo love to be played out.