Does 青少年を外出させないように refer to to letting a youth out alone, or in any circumstances?

Question

Over at Travel.SE, there's a bit of a debate on how to parse this piece of Tokyo legislation:

(深夜外出の制限)

第十五条の四

保護者は、通勤又は通学その他正当な理由がある場合を除き、深夜(午後十一時から翌日午前四時までの時間をいう。以下同じ。)に青少年を外出させないように努めなければならない。

I glossed the bolded part as "guardians... must endeavour to not let youth go out" late at night, which seems clear enough. Now the question is, does this refer only to youth going out by themselves (alone)? Or is it also illegal for the youth to go out together with their guardian if there is no "good reason" (正当な理由) for them to be out?

Specifically, the original question was asking whether it would be illegal for a visiting tourist to take their 15-year-old son out shopping or sightseeing late at night.

Answer 1

東京都青少年の健全な育成に関する条例:

第十五条の四　保護者は、通勤又は通学その他正当な理由がある場合を除き、深夜(午後十一時から翌日午前四時までの時間をいう。以下同じ。)に青少年を外出させないように努めなければならない。
2　何人も、保護者の委託を受け、又は同意を得た場合その他正当な理由がある場合を除き、深夜に青少年を連れ出し、同伴し、又はとどめてはならない。

One lawyer explains this like this:

禁止されているのは、保護者の許可なく、あるいは、正当な理由なく青少年を深夜に連れ出す行為です。

Tokyo Metropolitan Police Department says:

何人も、保護者の同意なく、又は正当な理由なく、深夜に青少年を連れ出し、同伴し、とどめてはいけません。

In other words, a 15-year-old boy needs BOTH 保護者の許可/同意 AND 正当な理由 in order to go out late at night, regardless of whether they're alone or with their parents.

When a children is accompanied by their parents, obviously there is a 保護者の同意 indicated by the second clause. But it does not necessarily mean there is also a 通勤又は通学その他正当な理由 indicated by the first clause. Importantly, the first clause is independent of the second clause, and 正当な理由 in the first clause does not include 保護者の同意 itself. (Otherwise, 保護者の同意 would be the only requirement, and the first clause would be totally meaningless!)

As far as I could find, there are no official sites which states that the sole existence of 保護者の同意 serves as the 正当な理由 for a youth to go out late at night. Thus, even when a children is accompanied by their parents, it can be illegal depending on the situation. The lawyer I mentioned says:

保護者同伴だったとしても、例えば、深夜遅くまで歓楽街や風俗街を連れて回るなどの行為に及んでいる場合には、やはり規制対象となることでしょう。

In reality, basically you don't have to worry at all if you want to climb Mt. Fuji overnight with an underage child. But you will certainly be questioned by police officers when you are hanging around Roppongi with a youth late at night. Also note that many leisure facilities (such as theaters) absolutely deny entrance of underage people after 11PM even when they're with their parents.