Smoke Blue no Ame Nochi Hare

Sakutarou got himself in danger while enjoying the nightlife when he was saved by Kuji Shizuka, his ex-colleague and rival who used to boast of being no.1 in sales. Kuji had resigned from work slightly earlier than him, and Sakutarou had envied him, believing that Kuji must be having a glorious second career now. However, after reuniting with Kuji for the first time in six years and though he's still as sarcastic as ever, Kuji now has long hair and a lethargic appearance and for some reason, he currently works as a translator...

(Source: Kadokawa, translated)