Volume 01 > Chapter 01 > Page 03 > Panel 03
Original Text:
1. よつば
2. おーっ！！
Romaji:
1. Yotsuba
2. O~~!!
English Translation:
1. Yotsuba
2. Wooah!!!
よつば:
This is the name of the main character.
When literally translated, the name "Yotsuba" (四葉) means "four leaves", as in "yotsuba no kuroubaa" (四葉のクローバー), which means "four-leaf clover".
Observing her green hair which is always styled into four pigtails, the author's reason to choose such name becomes evident.
おーっ！！:
This is an interjection (a word used to express an emotion or sentiment on the part of the speaker).
In this case, as you may have guessed by how it sounds (O~~ is quite similar to Wooah!!!), it shows amazement at something.
However, beware that it doesn't always show amazement. You've got to figure out its meaning from the context in which it was said.
The dash (ー) after the お character is called chouon.
It is primarily used to extend the vowel sound that comes before it.
In manga, the longer the chouon, the longer we pronounce the vowel that comes right before it.
Although it is supposed to be used with katakana only, manga directed at young children use it a lot with hiragana since it is easier to read that way.
As you may have noticed, there is a small tsu (っ) at the end of this interjection.
When the small tsu is placed at the end of words, it shows that the last syllable is spoken sharply, like an exclamation, especially with interjections of surprise or with commands. In these specific cases, the small tsu essentially fills the role of an exclamation point.
Many japanese writers also use the explanation point, either instead of or together with the small tsu. Here's an exemple:
Japanese: まて
Romaji: Mate
Meaning: This is a normally spoken command, "wait".
Japanese: まてっ
Romaji: Mate
Meaning: This is a sharply / shouted command, "wait! / stop! / halt!"