Not necessarily. Laws and regulations of other countries do not change in accordance to US laws and regulations.

A minor in Japan (considered anyone under 20), can get his/her own passport with just a single parent's (or guardian's) authorization. The minor doesn't even need to bring his/her parent along to the passport issuing agency (usually the county or ward office) to get one. All the minor needs is 6000 JPY, passport photos, a valid copy of his/her koseki shohon, and an authorization form from either parent/guardian.

Basically, the process of obtaining a passport for a minor (single parent) is still easy in Japan as it used to be in the US in the 1980s. No need of additional sets of headaches in consideration of "oh what if the kid decides to run away, parent decides to run away to prevent the other from visitation rights, etc. etc.)"