As of now, we don't know. Most people pair Ruka up with Hotaru, but there isn't isn't any basis on that. Ruka was always in love with Mikan, and took part of the love triangle between Mikan, Natsume, and himself. There wasn't much time for him to find another girl to fall for.
The cast of Mano tevas - 2007 includes: Tadas Gryn Edvardas Mazuolis Asta Preidyte Daiva Rudokaite Audronis Rukas Karolis Simaitis Remigijus Vilkaitis