>>14831769well if there's additional nuance it isn't being covered here yet. basically at this stage they just want us to be able to understand that 日本に行った時、着物を[買います/買いました]are both fine depending if u've already bought, but 日本に行く時、着物を買います would necessarily imply that u have a habit of going to buy kimonos and 日本に行く時、着物を買いまいた would imply preparation before leaving similar to 行く前に、買っておきました
so in the end all that really matters is that ur recognizing 買う is the verb that matters and other phrases should be thought of in relation to it
ur abandoning ur good friend in order to go sharting?
yes! great and hilarious content no?
good video