Although the stories are kinda different, both deal with high school relationships and the challenges that are faced within. Also, both appeal to a similiar shoujo audience.
Kiro Aso is an astounding artist who spends her days cooped at home or in art club room, avoiding all contact with others – especially boys. Rei Kashino is a popular motorcycle enthusiast who seems to have it all: looks, personality, and an endless supply of hot babes throwing themselves at him. When the two cross paths one day by chance, no one could have suspected how close these polar opposites would grow to be, or just how many obstacles their love would have to overcome...
mars and kare first love have many things in common. one of those things is both of the main characters have a good talent and both manga's have alot of obsticals in the reltionship. but if i say anymore then this i'll give away the excitment of both manga's if you haven't read them. If you like mars you will definitly like kare first love and vice versa :)
With a noticeable tan and bleached hair, Momo Adachi is a high school student who is frequently misunderstood by her classmates. She's accused of being a playgirl and is the subject of many rumors, most of which originate from her ‘best friend' Sae who is jealous of Momo due to them having a crush on the same boy. Momo's life only gets worse when Kairi Okayasu, who she once saved from drowning, decides to make her his own. Kairi coming into Momo's life only encourages Sae to spread more rumors about Momo and Kairi while going after Toji herself, creating quite a complicated situation for everyone involved.
Both series are about students who are in a complicated love triangle in which the "friend" of the protagonist is jealous and makes everything more complicated for everyone. Also, both series have a somewhat addicting suspense to them. The overall shoujo/romance theme of both is similar enough in that if you like one, you will probably like the other.
Both plots pack a love story worthy of reading till the end, just your regular patern of first loves going to the limits to be together, young guys thriving to make their dreams come true with their main girl by their side, these are series where the majority of the attention goes to the male character but the female chars have their crusial parts in the stories, Kare first love can be taken to a young reader and still be able to identify with the story, as Sensual Phrase will delite you if you just want more than little kisses and hugs.