L is (was) a project of Hiroyuki Usui, who in some very distant past used to drum for (Fushitsusha), although I don't think there's any recordings with him on it. He was also in some very early incarnations of Ghost, (Kyoaku no Intention) and Marble Sheep, apparently, but again I can't find any albums featuring Usui. Later he popped up in Landfall (whom I don't know anything about) and Ken'ichi Takeda's political 'anti-pop' group A-Musik. The first tangible trace of his art that I'm aware of is this lost little gem, 'Holy Letters', which was released in 1992 on his own label Holy Castle Records, as an 11-track CD + 7" package. Presumably it didn't do much back then - in fact it wasn't until a decade later, when some copies somehow ended up at Aquarius Records, that this album got noticed, and even got an elegant reissue (with bonus track from the same sessions but without the nice over-sized packaging) on VHF Records (in 2004). New linernotes were provided by Ben Chasny (Six Organs of Admittance), who didn't stop at that but formed a duo with Usui named August Born (their only, untitled CD was released on Drag City in 2005). In 2009 Six Organs released a split-LP with Azul, yet another of Usui's projects (with - among others - Masaaki Motoyama, who already played the 'cello on 'Holy Letter') on PSF. Usui also seems to be part of a band called (Gendai Sokkyo, or simply 'contemporary improvisation') these days. So yeah, he seems to know his way around the hip & freaky side of the Japanese underground.
Mention of Fushitsusha, Ghost etc. might have given you the wrong idea though. This is in fact a very relaxed folk album, intimate and moving, featuring gentle bluesy guitar (the opening track is Blind Willie Johnson's 'Cold Was the Ground!'), drones, field recordings, throat singing, didgeridoo... and a surprise guest appearance of Taku Sugimoto on 'Troll'. An album that I've often returned to over the years, one you can't afford to let slip under your radar. Gorgeous. (source)