Tottoko Hamtarou OVA 1: Hamtaro no Otanjoubi - Mama wo Tasunete Sanzen Techi Techi
English title: Hamtaro: Hamtaro's Birthday! - 3000 Hammy Steps in Search of Mommy
Japanese title: ハム太郎のおたんじょうび 〜ママをたずねて三千てちてち〜
Type: OVA
Episodes: 1
Source: Unknown
Genres: Adventure, Comedy
Studios: TMS Entertainment
Duration: 44 min
Rating: G - All Ages

Laura tells Hamtaro where he came from yet Laura thinks it is not true, just in time for his birthday, Hamtaro sets out with Boss and Oxnard to visit his mother to see if what Laura said is true, while the other Ham-Hams set up a surprise birthday party for him.

(Source: Wikipedia)