
Quick answer — Shizuka Hasegawa voices Yutaka Kobayakawa in Lucky☆Star, Sayaka in Whispered Words, Tomohane in Inukami! and 3 more characters.
Shizuka Hasegawa voices Yutaka Kobayakawa (Lucky☆Star), Sayaka (Whispered Words), Tomohane (Inukami!), Yukino (Nagasarete Airanto), Tenchi Koganei (Sumomomo Momomo: Chijou Saikyou no Yome), Lulu Hinagiku (Futakoi).
Yutaka Kobayakawa is voiced in Japanese by Shizuka Hasegawa.