Oh, and another example: Corseltel no Ryujitsushi (to order wildly divergent romajizations of コーセルテルの竜術士), which runs in the all-ages female-focused Comic Zero-Sum, which I suspect means older shoujo/younger josei in practice. It's not suddenly childcare, but the young dragon mage does spend most of his time looking after seven anthropomorphic toddler dragons, who've been sent to him ostensibly to teach but which at that age amounts to in-house childcare. Stories are a mix of comic childhood mishaps and fantasy adventures that come looking for him (because they know where he lives).

---L.