Please consider the following:

```
Warrior is ウォリアー： this vowel sound "a" changes to ”オ"
Work is ワーク:this vowel sound "o" changes to "ア"
Chariot is チャリオット:this vowel sound "a" stays "ア"
Corridor is コリドー:this vowel sound "o" stays "オ"
As for the other words that don't start with "w", "a" stays "ア", "o" stays"オ".
Margin is マージン："a" stays "ア"
Border is ボーダー:"o" stays "オ"....etc.

```

But only the words with starting with "w" are opposite. Do you know why?