Why is everyone giving me tissues?
In Yazuka 0, I often see people with the 'You can talk to' bubble above their head.
Being a good open world player and wanting to get all the quests, I talk to them, just to be given tissues that seem to have no use.
So... why is everybody giving me tissues?
It should be related to real-life https://en.wikipedia.org/wiki/Tissue-pack_marketing :
Tissue-pack marketing (ティッシュ配り) is a type of guerrilla marketing that is a phenomenon in Japan. Companies use small, portable tissue packages to move advertising copy directly into consumers' hands. About 4 billion of these packages of tissues are distributed on the streets annually in Japan—largely outside of subway stations. This industry generates sales in the range of ¥75 billion annually.