Nisekoi:

-Similar plot where the MC is surrounded by girls -In both the anime's , the MC has only one object which serves as a clue , in nisekoi its a Pendant Lock -Both are Comedy-Romance 

They had similar characters, there's love triangle happening in both anime that you would like. The main heroines are Tsunderes and both are loveable, I really think if you liked one of the animes than you would like the other one. 

Both shows have the exact same type of characters.- Nice main character- Loud, physically abusive tsundere- The calm, nice one - The yandere- The side character who knows the tsundere in some way and is the last one to become interestedBoth shows have a strong comedy focus, although I think Nisekoi dives a bit deeper into the romantic aspect of rom-coms. 

It has the same vibe and comedy but Nisekoi is way better than Bokutachi wa Benkyou ga Dekinai id say 

-Bunch of lovable charachters -Cringe moments -Harem This one is ecchi just to note ... 

They both have almost the same plot in the story. 

Both have something between a man and women in the past. Now that they are in highschool , meet once again after a long period time. Most personality are come from what they were like when they were kids - Same Romance and Comedy - A lot of drama - Ofc the girls are cute :3 

Nisekoi and To Love-Ru are popular harem/ecchi Jump manga with successful first seasons. If you like one, you'll like the other. Both second seasons, though, are shorter, more comedy-centric and feel like a drop in quality compared to their respective first seasons. I'd still recommend both if you enjoy harems, ecchi and all that, though.