They first meet 8 years back in that flower garden, but they were not lovers not friends, the uke was in love with Sano. And Sano loved the uke as well but he never told him, and that's why he put that tattoo on his so he ca have a part of him always with him. Something that will not change. So the uke didn't know that Sano loved him. He was finally honest before leaving.
Hope i did clear the things a little
Nor lovers, nor friends* sorry i have this auto correct on my phone... And is changing mu text
Niiice~ I reread that last chapter after reading your explanation. everything makes sense now, thank you so much :*
I don't understand the last chapter.