Shugo Chara!! Doki Episode 46: Tadase and Ikuto! The Horoscope of Destiny!
Episode 46 of 51 of Shugo Chara!! Doki, aired August 22, 2009, 25 minutes. Available with English subtitles and dub where released.
Episode summary
When Tadase was little, there was a time when Ikuto and Utau lived together due to certain circumstances. The three of them used to play all the time but when Ikuto took the Dumpty key, he disappeared. The old Ikuto talked to Tadase. Thinking of this Ikuto, Amu and the Guardians go to find him! Source: crunchyroll