Responses

If you haven't noticed yet, his "hardships" at the office, are the work of his "girlfriends" grandpa. Grandpa is using him, to clean out the rubbish in the company, therefore, polishing him as the son-in-law who will take over, but unknown to grandpa, he will end up writing again and leave that workplace in the dust!!
THIS IS NOT A SPOILER, THIS IS ONLY WHAT IS MY OWN HEAD. Take with salt please.
In my opinion I think the story it self would of done just fine without the highschool girl just him having to deal with the hardships of his work cuz of ppl like that worthless superior who causes a mess and him being able to rise the ranks would have been enough though I have nothing against her she is kinda funny not complaining still like this story XD