>>17
「約束」かは争いあるけど「口約束」があったのは本当だろうな
https://weekly-economist.mainichi.jp/articles/20220902/se1/00m/020/005000d

https://www.asahi.com/sp/articles/ASQ4N3RW5Q48UCVL01X.html

https://note.com/yuichihosoya/n/n778caf033b27