The happy-go-lucky dude. Yup, that's why people call him the 'Lucky Sengoku' right?
Yes, he is a huge flirt.
Super duper huge flirt. And you disliked him for that.
You were just happily strolling around the beach when you bumped into him. I mean, hey, you appreciated his help and all that.
But he didn't need to flirt with you. There were like, three or four girls around him.
No way were you joining that harem.
You rolled your eyes at his petty attempts of flirting with you.
Let's say you were the first girl to ever turn him down.
He became disappointed, and confused.
Nobody turns down Sengoku... well, maybe Akutsu does. But I'm getting off-topic.
He felt like he ran out of luck when you ignored him.
Just like what happened when he lost to Kamio.
He reinvented his tennis, yeah he took boxing lessons, remember? That makes him not-so-lucky anymore.
So he just says 'Lucky!' because that's his catchphrase.
So he did the same with his... flirting.
He only made moves on you. And he desperately tried hard not to be distracted with other cute girls.
The more he becomes determined with making you fall for him, the more he gets attracted to you.
So when he had the chance to say it, he confessed to you.
At first, you thought it was just another one of his lame jokes and him teasing you.
But when you looked at him straight in his eyes, he was so serious it left you speechless.
He used this opportunity to give your lips a peck. It was his lucky day to confess anyway.
Wait. It reminds me of Kiseki no Sedai's Sharpshooter, Midorima. The megane-green-haired dude who was so addicted to lucky items and all that.
Oops, wrong anime.
Like I said, I shall stick to Tenipuri.
'Lucky~! You're finally mine~!'