Quick answer — Hiroshi Watanabe worked on The Law of Ueki (Director), Tying the Knot with an Amagami Sister (Assistant Director), You're Under Arrest! (TV) (Series Composition) and 14 more anime.
Hiroshi Watanabe worked on The Law of Ueki (Director), Tying the Knot with an Amagami Sister (Assistant Director), You're Under Arrest! (TV) (Series Composition), Hell Girl: Three Vessels (Director), Sankarea: I, Too, Am... A Zombie... (Color Design), Sankarea: Undying Love (Color Design), Hetalia: The Beautiful World (Director), Sankarea (OVA) (Color Design) and 9 more.