Miyazaki, great name by the way.
I cycle to work and back - I have two bikes, one MTB and the other a ladies road bike. The only thing I would really like if I was actually buying a bike to ride to work - would be a chain gaurd.
The reason being then I wouldn't have to faff about either putting my trousers ( I mostly wore trouser to work any how but now always) inside my socks to stop the trousers getting ripped in the chain and me falling off. I could use clips - but they always seem to slip or I end up lossing one.
So if you are going out to buy a bike think about whether you would like a chain gaurd to prvent all the hassle and the ability to wear a skirt cycling.
I also have great panniers that I can just slip my handbag in one side and the other side you would in your case be able to fit a change bag etc for dc.
Something like this
cgi.ebay.co.uk/LADIES-DUTCH-STYLE-BIKE-New-Fully-equipped-FREE-P-P_W0QQitemZ260250808296QQihZ016QQca tegoryZ33503QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
It has a skirt protector and a built in lock for the bike which saves having to carry the lock.
cgi.ebay.co.uk/Ladies-Traditional-Dutch-Bike-Made-in-Holland_W0QQitemZ150257813836QQihZ005QQcategory Z33503QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
I would advise to get used to a few trips on the bike before you put the seat on for dc, the difference with a child moving about in a bike seat is a bit odd.
Or this type - hmm wishing for me now!!