The answer to your question is in the next chapter (ch. 10, pg 14). Asami had refused to help Akihito, so Akihito attempted to use sex to manipulate him (which failed because Asami was aware of what Akihito was trying to do). Unfortunately, the translation for that chapter was not good. Here is the official translation for that page*:
"What the hell am I doing? Did I really just try to sell my body to get what I needed? Coming to Asami to beg for help... ugh, I'm so stupid. He gave me a lecture and then soothed me with sex."
At that time, Akihito knew Asami was someone he should avoid (and yet he couldn't resist the temptation of attempting to bring him down from time to time). He hadn't fallen for Asami quite yet. For Akihito to come to Asami, swallow his pride and use sex meant he was truly desperate.
*Vol. 3, SuBLime edition. Juné's translation is almost the same
I am confused with chap 10 too so i don't understand why does uke sleep with seme. So uke wants to exchange by using sex to help his friend?
The simple answer is yes, Akihito was using his body to get what he needed-- to get Asami to help rescue his friends. But there's a lot more going on in these 2 chapters that explain WHY they ended up having sex while all this stuff was going on. Akihito did it because he thought his plan had a small chance to work*. Asami did it to keep Akihito from running off and getting himself killed (Asami once used a similar method on Fei Long to keep him from running off-- this is yaoi; don't question the logic).
Asami knew the sex would be only a temporary fix, so while Akihito was in the shower, he got a hold of some sleeping pills and slipped them into Akihito's soft drink to knock him out.
*Asami slipped up and gave away that he did actually care about Akihito, and then tried to walk it back by saying Akihito didn't mean anything to him, but Akihito had already caught the slip up.
Oh i understand. Thanks for your reply. You are so kind when you explain it to me carefully
I’m glad I gave you a straight answer then instead of a warped version. And yw
In vol 3 chap 9 why does uke sleep with seme while his friends are in dangerous? Is it because uke was fall for seme?