Let's pretend that Ash is real, for a moment. Right now, he's ten-years-old. There would be no possible way to determine his sexuality, simply because he hasn't reached the age where he develops feelings for others. But given that he has shown attraction to at least one girl in the series - despite how old the episode where he did is - we can assume he's straight, keeping in mind he hasn't shown any attraction to any males.
Now, let's jump back to reality again. Ash is a cartoon character in a children's cartoon. He has no sexuality. And if for some random, awful reason, an anime writer or director decided to make a comment on Ash's sexuality... what do you think he'd say? Why, that he's straight, of course. And that'd be the only actual indication of Ash's sexuality.
You're comparing apples to oranges. Pokemon and Sailor Moon are two completely different things.
Now, let's jump back to reality again. Ash is a cartoon character in a children's cartoon. He has no sexuality. And if for some random, awful reason, an anime writer or director decided to make a comment on Ash's sexuality... what do you think he'd say? Why, that he's straight, of course. And that'd be the only actual indication of Ash's sexuality.
You're comparing apples to oranges. Pokemon and Sailor Moon are two completely different things.
