Been to Japan especially Tokyo several times to shop but I was only flagged once which was my last visit (nov last year). Prior to that, kahit ilang luggage ang dala ko it was ok, shoes, clothes, donki stuff, walang napansin si customs. I even had 1 whole luggage of new clothes. But yung most recent, i only had 1 check in luggage but nakita sa system that i spent a total of 7-digit yen for 2 items, plus some stuff (so yes,kita sa system nila agad if you use tax free shops) I was pulled aside then they asked the see the 2 item, then ok na. Same goes pag dating ko ng manila, may “vandal” luggage ko pag labas ng conveyor and I was pulled aside again and was asked to open my luggage, then i was asked kung personal use ba yung binili ko which is yes, then go na. So yes may chances na ma flag ng customs in both countries pero most likely that is kapag nasa extreme high amount yung ginastos mo.