Hide is already 70 and Tomohisa died 20 years ago .. that makes Hide 50 when Tomohisa died. Considering that they were just in their 20s (or early 30s) during the manga, that means they shared blissful living together for at least 20-30 years.... But yes, the author could have showed those happy years, and not when one is living while the other has passed on a long time ago.
But I did like that Tomohisa remained in Hide's heart and faithful to the promise they made even 20 years after Tomo passed away. That just conveyed the deepness of their bond after their earlier trials
... did I just read? What was this for? Two bad things about the extra:
1- Clearly it's the tragic/sad ending;
2- We get this ending without the story behind, in other words, we don't know anything about their life together in Germany, we don't know how he died and then we have to deal with this painful ending... this is so wrong. I'm mad and sad.