Part of Gakken Masterpiece Animation (学研の名作アニメ), which seems to be some collection or specific tv block multiple anime were produced for like Cello Hiki no Gauche (1998) For some more information refer to http://www.videomarket.jp/title/271002/006 Production seems to have been around 1998 and following years. Note that all of this is speculation and very lil founded in fact. Information about this on the internet is sparse at best.