Family.
Danny thought he was not the right man for family.
He had a family once or better twice, but he screwed up with both.
Family was him with his parents back in the Jersey, but since it moved he barely heard form them.
Family was Rachel and him, holding tight on each other in front of Grace's first smile.
This is what family meant to him, and he knew he had screwed all. He left the life to melt down those bounds, like ice in the sun. Now the only thing he was left with was Grace. Grace was not his family, Grace was a lot more: she was his whole life. She was the reason he left all his old life behind without a blink and moved across the continent.
There had been rough months when he first arrived in Hawaii, but now with Five-0 he had found something he thought lost forever. He felt safe, he felt he could trust someone again, he felt he was not alone anymore. There was nothing he would have not done for these people and he knew there was nothing they would not do for him. Those were the feelings he was used to call family, but he was not the right man for family. He was afraid that if he started calling them 'his family' he would have ruined all, again.
Then he found out that word: 'Ohana'. Ohana meant family, but in another language it was not as scaring. Ohana was the right word.
Ohana was everything he found in Hawaii and he was sure it was the only thing he would never lost.
To my Ohana
Debh