Or, the suitors go to even more unhealthy extremes than usual, leading to the invoking of Double Standard: Rape, Female on Male on a regular basis or Kenta becoming violent in self-defense.
Kenta acquires a large number of female friends, but none are overtly interested in a romantic relationship.
Kenta is being pursued by three or four unusual young women.
Kenta is Cursed with Awesome, forced to attract infinitely many women, only to be unable to love them back. He might already have a girlfriend, is gay or asexual, or finds the constant belittling and one-upping of the other girls to be unattractive, explaining his lack of interest.
He is overloaded with fear.
Kenta: "TOO MANY!"
Kenta realizes that with these bizzare girls comes equally outlandish trouble. Kenta's house becomes a battlefield on weekly basis, with Loveliel fighting hell spawn, Rumiko stuggling against hunting shinigami, ER-7 driving away the evil organization that wants the hidden data in her memory chip, Lunaru trying to avoid alien hunters, Raymeister battling the Monster of the Week and C'thiala devouring Starfish Aliens send by her Papa WolfEldritch Abomination. None of them would bother him if it weren't for his harem.
Zig Zagged: Initially, each girl in Kenta's harem has hidden agenda and will leave him once one fufill her goal. However, spending time with Kenta made them realise he is actually a good guy and actually fall for him.
Enforced: "We hear that fans really like to ship Kenta, but there are so many different pairings. Let's give him a whole bunch of girls so there's no definite couple."
Lampshaded: "See that guy with nine different women fawning over him? Yeah, he doesn't love any of them."
Invoked: Kenta is a Casanova, and is wooing all these women intentionally to stroke his ego.
Exploited: Kenta is the son of a millionaire and the girls are actually thieves who are using their proximity to Kenta in order to plan a major heist, using their harem antics to distract people from their plans.
Discussed: "Kenta, do you really want to save her from that monster? You know she'll want to join the harem then..."
Conversed: "This guy has more hot women fawning over him in one week than I'll ever even see in my life, and all he can do is moan about it?"
Eventually, the competition over Kenta gets so fierce that some of the girls decide to try whittling down the field through murder. The deaths cause others to step back, ask what they found so attractive about him anyway, and give up. Kenta is left completely alone... or worse, with one murderous suitor who won't take no for an answer, assuming she wasn't killed or arrested.
Or, Kenta himself eventually snaps and starts forcibly ejecting the girls from his life by whatever means necessary.
Or, all the girls in the harem automatically lose interest once Kenta does.
Or Kenta, is gay and trying to find a boyfriend but can't because there's a infamous group of girls that are in love with him and thus everyone thinks he's straight.
Or, Kenta is disowned by his family for leading a "sinful lifestyle", leaving him barely able to support his Pretty Freeloaders.
Reconstructed: Despite any initial tension within Kenta's harem, all of the girls eventually become close friends with each other, respecting each other's feelings towards Kenta. Likewise, Kenta becomes close friends with all of the girls, even if he can only pick one to be his girlfriend.
While the girls scheme and connive to eliminate each other, Kenta goes emo over his inability to love a woman and how they never leave him alone.
Kenta can't decide who he loves, and has a place in his heart for all of them... And they 'won't stop fighting over him. He's sick of watching the women he loves make each other (and themselves) miserable competing for him... But he can't just say so, or he'll have even more pressure to pick somebody... and lose everyone else.