Both OSTs for Gulliver Boy anime:

Kuusou Kagaku Sekai Gulliver Boy ~Judau no Saigo~ (PHCL-1004)
~Densetsu no Gulliver~ (PHCL-1005)

I wasn't very interested in this first, but then I found out Hiroi Ouji, the genius behind Tengai Makyou series has written this so I must see this.

Also, Tanaka Kouhei.

I'm looking for Gulliver Boy's OP/ED Single, I can't find it anywhere, I hope somebody can help me :(
https://vgmdb.net/album/39272