Shikamaru first met Ace at his own birthday party back in September. He'd never met him prior to that, which was a little annoying, but Ace made a good first impression. He's the cheerful and easy-going sort, easy to get along with. The kind of guy Shikamaru might not go out of his way to say hi to, but wouldn't mind hanging out with if they ran into each other.

The one time he did seek him out was over something more serious. Ace's question about whether or not blood matters lead to a discussion that revealed some deeper intricacies to his background, including that he might have even died. Shikamaru's not sure if his advice had any impact, but he hopes that Ace will come to better terms with what's bothering him. He seems to have good friends who can help him with that.

All and all, Ace is a really likable guy for a pirate, with both his appreciation and sympathy. He also makes a mean grilled mackerel, which to be fair probably contributes to about 40% of Shikamaru's opinion of him. At least it's in a positive direction.