A smile graced Buddha's face, and he was not even upset with the remark about him being boring or behaving like an old man. He had a monotonous life with nothing else to do but train like an army man. So he did enjoy the surprise visit from a genuine friend.
Even if not for these reasons, Buddha would not get angry at him.
Getting angry at other's was never in his dictionary. That was the reason Park Sun Woo got the nickname Buddha.
Lack of temper was also one of the reasons Min Jun fell for him long back.
Buddha appreciated Yama using a ruse of discussion regarding the 'lack of proper effort' to call him to the chief commander's office for a talk. For a minute, he also believed he was not putting adequate effort.