Hiro: Nemesis!
Daphne: Stop calling me that. My name is Daphne.

Hiro: Now the hard part...
Ando: Why are you smiling?
Hiro: It's exciting! This is our chance to change the future.
Ando: But how? How will we know what to do?
Hiro: I have Mr. Isaac's comic book. It's not finished. It only has the pictures, not the words.
Ando: We could be talking about anything.
Hiro: Let's go ask Mr. Isaac. He'll know what we say. (yelled, in English) Don't worry New York! We will save you!
[over the phone]

Hiro: Now you know what it's like to be killed by your best friend.
Ando: Okay, now we're even.

Hiro: Oh no. I broke history.

Hiro: The past isn't a very safe place.

Hiro: Tonight, we will attack. Three of us against an army. But even with powers, I fear for the sword smith's life. And for Yaeko. The woman I love, but cannot have.

Hiro: We are badasses now.
Ando: Yes, we are very badass.

Hiro: We are searching for a formula that...
Adam: A formula? I knew it'd come back to bite them in the ass one day. Even I told them to destroy it.
Ando: So you know who would steal it?
Adam: Maybe... If I tell you, what's in it for me?
Hiro: When we have finished our mission, I promise to put you in a most spacious cell.
Ando: With a window!
Hiro: And a vent.
Adam: Forget it.
Hiro: Okay, back you go (Squeezes eyes to bend time)
Adam: Wait! (frustrated) You little Japanese Nazi! Let me think! Let's see, off the top of my head, I'd say your villain is Angela Petrelli.
Hiro: She's the one who asked us to find the formula.
Adam: I see. Well then, I'm fresh out of ideas.

Hiro: What are you doing?
Ando: I'm being awesome!

Hiro: Why is everything so purple?

Hiro: Yatta. (Note: Throughout the series, Hiro says "yatta," which means "I did it" in Japanese)

Hiro: You are the hero Kensei?
Takezo: My name here is Kensei, but no one's ever called me a hero before.

Hiro: You cannot bribe a hero. My heart is true. My spirit unbreakable.

Hiro: You don't understand, I want to be special.
Ando: We are not special. We are Japanese!

HRG: Compared to the life I had, normal is a pretty nice vacation.