Both are BLs with a light-hearted tone. Love By Chance is less comedic and more serious, but still has its funny moments. Both have lead's who are explicitly gay, rather than 'gay-for-you' and supportive mothers who play a role in the series.
Same actor. Same comedic/light tone. Both are short, easy entertainment. Puppy Honey has two main storylines with a straight couple featured as well, but if you're not into that it's also easy to skip through and still follow the BL.
Both the stories ha gay character and gay relationship. They are so interesting and funny with gives a wow factor to the story.
What if Gump didn't have Nai before going to help out his new roommate?
Both BL stories are centered around the effects of having a new roommate - the roommate being the relative of a close family friend.