A few favorite Japanese kids' songs - with some listening practice

Ton Ton Tomato-chan (Pow-Pow Little Tomato)
Listen for the use of と to mean "with," as well as very child-like pronunciation of あそぼう (let's play) and かくれんぼ (hide and seek).

Omocha No Cha-Cha-Cha (Toys Cha-Cha)
Listen for さよなら (goodbye) and こんにちは (hello).

Anpanman No Okao (Anpanman's Face)
Listen for the use of the honorific お in the body parts. おめめ instead of め for eyes, おくち instead of くち for mouth, and おはな instead of はな for nose.

Inu No Omawarisan (Doggy Cop)
Listen for どこ (where) and ～ても form of verbs ('even when').

Donguri Koro Koro (Acorn Rolling)
Listen for いっしょう　に　あそびましょう (Let's play together).

Genkotsu Yama No Tanuki-san (The Badger From Genkotsu Mountain
Listen for また　あした　(see you tomorrow).