It's a full series! Created by Production I.G. and produced by Sugar & Rockets, there were four games on PS1 that were all released in 1998 (Double Cast, Kisetsu o Dakishimete, Sampaguita and Yukiwari no Hana, all which got ported to PSP in 2005), and then Scandal on PS2 in 2000. There's also Blood: The Last Vampire that released on PS2 in 2000 (and ported to PSP in 2006) and Surveillance Kanshisha in 2002 (not Yarudora, but same team), but they were released after Sugar & Rockets was no more.
And yeah, there used to be a time in which SCEI collaborated A LOT with Production I.G., besides all of those, they also worked on Ghost in the Shell (1997), The Granstream Saga, Wild Arms 2, Love & Destroy and Popolocrois Monogatari II.
Arc Entertainment (Arc the Lad III, Brightis), Contrail (Ore no Shikabane o Koete Yuke, Boku no Natsuyasumi) and Sugar & Rockets (PopoRogue, Poketan) were all SCEI production subsidiaries that operated separate from the production division, like Polyphony Digital, but they focused on producing externally-developed games instead. Sugar & Rockets did make some games internally, like Pocket MuuMuu and Robbit Mon Dieu (which is basically Jumping Flash! 3).
They were established in October 1997, and got absorbed by the main SCEI in August 2000, shortly after SCEJ (the sales and marketing division) took over the game production operations in February 2000.