In the aftermath of sleeping with his incredibly girthy coworker Baek Youngchan, Seo Hyunsoo is in a panic. Youngchan’s nonchalance doesn’t help matters. Shouldn’t it be a bigger deal that the two slept together after Hyunsoo got wasted at a work dinner? Instead, Hyunsoo and Youngchan agree to keep things casual…including the sex. With the arrival of a new team in the office - comprised of Hyunsoo’s ex-coworkers - everyone’s workloads increase, leading to first Youngchan, then Hyunsoo falling ill. As they nurse each other back to health, they realise their feelings are much stronger than casual. But can they own up to their feelings?