Definitely an interesting first chapter. Not much more to say, but I will be following this one.

Take care, good luck, and I look forward to your next update.

good first chapter i look forward to more.

A good start.

seems cool to me. faving and following to see more

any hopes for robin and luffy?

Well. good starting. I like your writing and I agree everything you said in first part. Actually plasma is a bit too powerful bıt I liked that too. Keep writing.
Oh, and please do a lot of storyine changes. Otherwise it will be boring.

Looks promising :D
I don't have much insight to offer (I like being surprised by writers ), though I suppose I could point out there's a few reasons Kaya could decide to join: her manor is destroyed (or everyone inside dies), her relationship with Usopp evolves enough to make her want to follow him (or make him want to stay with her, which convinces her to leave with him instead), she actually signs off her fortune (to the villagers to pay for reparations, for example), or she feels the need to help other people in her situation (after hearing a bit of Nami's past, or simply befriending the crew and learning more about the world out there...)

The Sun Sun Fruit sounds interesting, and I usually enjoy stories with additional crewmates, so I'll keep an eye on this one ;)

This is really great, looking forward to more and how seeing how and when Luffy decides to break out the big guns.

Keep going 0~o

Love it! Sun man huh? Well Lu always was a ball of sunshine xD! Waitin' for a new chapter!

Enten Enten? As in "Burning Heaven"? Why not name it the Nichi-Nichi no Mi? It would directly reference the sun (Sunday in Japanese is Nichiyōbi) a lot more than "Enten".

And Rokushiki?! Geez, little much ain't it?

Question: will Luffy become weak at night, or if the sun is obscured by heavy cloud cover? This might make him more vulnerable to the Yami Yami no M and during his trek at Impel Down sure, but the point of Devil Fruits is that it should not make the user totally invincible in combat. More dangerous yes, but not invincible.

This is very good, but maybe rokushiki on top of a devil fruit that is in a superior relationship to akainu's is a bit over kill. Other that it could be the plasma plasma fruit or star star fruit or something like that. I hope you update soon.
P.s. For the crew and pairing I would suggest Vivi, do I really need to list all the reasons why that would be awesome?

i like the slightly more observant and understanding luffy. gives a bit more reason behind his decisions. great start!

Why not do both a crew member and paired with Usoup

I really like this story so far, I especially like the uniqueness of Luffy's fruit which tend to just be water or somebody else's logia. As you mentioned Luffy is pretty clever with his powers so maybe he could utilize some kind of rocket punch by directing his power out of his elbows (think Pacific Rim). I like that he met Nami immediately which is a nice change pace from other fics where he either meets her when they are kids or meets her at the usual place.

I do have two criticisms. One is that I feel even a more serious Luffy wouldn't make a big deal out of the reveal of his grandfather. I feel like Luffy, as a simple guy, would think of Garp simply as his grandfather instead of some marine hero. Two is that I think him knowing Rokushiki is kind of unnecessary when he already has a pretty significant power. For example he could have directed his plasma powers down to rocket up instead of using geppo or simply taking the bullets like he did in the original story which would have still scared Nami but also demonstrated his power. Though Morgan chopping plasma is still very entertaining to me cause that guy's a dick.

Otherwise a very strong start.

interesting!