Kaeru no Prince-sama by Panco.

Summary

Plot: Socially awkward Aono was perfectly happy working in Quality Control but as fate would have it he’s been transferred to the Sales Department?? As if being ridiculed by his co-workers for his nervous stutter isn’t bad enough, he’s thoroughly mortified when the departmental star Gouzaka overhears him having a breakdown on the roof. But no matter how often he pushes Gouzaka away or how fast Aono runs Gouzaka is always there by his side… Has this timid frog finally found his Prince Charming?