Source: http://privatter.net/p/1443038
What is being said to him is in [brackets].
Sometimes he has multiple responses indicated by (numbers).
The (time of day) may affect the responses as well.

[Osomatsu] Can you stop eating my dried sardines?
[Karamatsu] Shut up, Shittymatsu!
[Shittymatsu] Hah?
[Choromatsu] No matter how many times you go to a handshaking event, they (the person you shook a hand with) will never remember you, Choromatsu-niisan.
[Ichimatsu] My name? Matsuno Ichimatsu.
[Juushimatsu] You wont practice your swings today?
[Todomatsu] Hey, Todomatsu-kun from Keio.
[What is your name?] (1) It's Ichimatsu. Whatevermatsu is fine too...
(2) My name? Matsuno Ichimatsu (Apparently the text says "boku", but he says "ore".)
(3) I'm the fourth son, Ichimatsu...
[Please treat me well (yoroshiku)] You're being over-familiar.
[Nice to meet you] There's no need for introductions. We won't meet again anyway.
[It's been a long time] Have we met before?
[What is your gender?] Trash.
[How old are you?] What will you do (with that info) if I tell you?
[Where are you from?] Earth.
[What is your birthday?] I don't have one.
[What is your hobby?] I like... playing with cats, I guess...
[What do you like?] Cats.
[What do you dislike/hate?] ...Everything.
[What is your favorite food?] ...Chicken wings and such.
[What is your favorite type? / What are you into now/current obsession?] ...Cats.
[Do you have someone you like?] I do have lots of people that I hate.
[Who do you like?] ...Not interested.
[Do you like me?] I don't like people. They'll betray you just like that.
[Do you hate me?] ...Obviously.
[Who am I?] Did you forget your own name? Right.
[If you could have one wish come true] I want to live my life surrounded by cats...
[If you could use magic] It's not here. (Kind of a vague answer, I think he's saying magic doesn't exist.)
[What are you doing?] (1) I'm feeding the cats.
(2) You can tell by looking, right?
[What are you doing right now?] (1) Feeding the cats.
(2) Breathing.
[When do you go to sleep? / When are your sleeping hours?] When I'm not awake.
[Are you gonna sleep? / Aren't you gonna sleep?] I'll go and prepare the futon with Todomatsu and the rest soon... (Will start the alarm function.)
[Good morning] Good night.
[Good morning (in English)] (During the morning) Thanks for trying to look cool when greeting me (The way he says it makes it sound sarcastic.)
(During daytime) I'm gonna go go sleep now though.
(During the evening) Stop it. You'll remind me of Shittymatsu.
[Good day] (During the morning) I just woke up though.
(During daytime) Could you not call out to me if you don't need anything?
(During the evening?) Thanks.
[Good day / Thanks for your hard work (said at the end of day of work etc.) / How do you do? / Howdy] (During the morning) Good... morning.
(During daytime) (1) Hey...
(2) Thanks.
(During the evening) (1) Thanks, good evening.
(2) Good evening...
[Good evening] (During the morning) Good morning... Ah, did you just think I'm trash for waking up at this time?
(During daytime) Thanks.
(During the evening) I was just about to go to sleep though.
[Good evening] (During the morning) (1) Good... morning.
(2) Morning...
(During daytime) (1) Thanks.
(2) Hey...
(During the evening) Good evening...
[Thank you, thanks] (1) Thanks.
(2) For what?
[I'm sorry] I'm sorry too. (That line from ep. 5)
[I'm going now] ...Mhh
[I'm back] Why did you come back?
[Thanks for the meal] What are you gonna do with the leftovers?
[Good night] Wouldn't you be happier if you never woke up?
[Good by / See you again / Bye-bye] Forever?
[See you tomorrow] ...You say that, but you won't come, right?
[I'm free tomorrow] I'm free all year round.
[Happy birthday] It was unfortunate that I was born, right?
[Today is my birthday] Huh...
[Morning] (During the morning) Morning...
(During the day) (1) Hey...
(2) Thanks.
(During the evening) (1) Good evening...
(2) Thanks, good evening.
[Feel good/ Fun/ Celebrating] Isn't that nice?
[I'm sleepy] (1) Why don't you go to sleep instead of saying it.
(2) Yeah, good night...
[I want to rest] Why don't you go to sleep already instead of saying it.
[I can't sleep] Well, then stay awake?
[I don't want to wake up] Then keep sleeping?
[I want to eat] Then just eat something?
[I want to eat a snack] Even though it's not time for lunch yet?
[I'm late] If you take the day off, you won't be late anymore.
[I overslept] How about you go back to sleep?
[I went back to sleep] And now feel free to do it once more.
[I want to go to the toilet / I want to take a dump] Just go already?
[I don't want to go to work] Isn't it cause you'll have to come back, that you don't want to go?
[I don't want to go to my part-time job] I don't think you need to have a part-time job.
[I don't want to study] Then you don't do it.
[My homework won't end] Then isn't it better to not start it in the first place?
[I passed a test] I don't want to fail, so I didn't take it. (Not 100% sure who he is referring to here.)
[I passed] That has nothing to do with me.
[I want to go home] Why did you come?
[I'm going to take a bath] Ah, the bathhouse will close soon.
[Feel good] (1) Free/bored/nothing to do.
(2) I'm gonna give dried sardines to the cats.
[My heart is beating fast / I'm nervous] That just means your heart is working.
[It's hard / Tiresome] It's always like that.
[Difficult / Angry / Frustrated] The meaning of garbage like me living...
[I'm full] You'll feel hungry again in no time.
[I'm tired / This is a pain] You're always tired.
[Are you tired?] Garbage doesn't move, so I don't get tired.
[Free time / Bored] Are you a NEET as well?
[It's nothing] Then don't say anything.
[I messed up] You did it on purpose, right?
[Interesting / Funny] How?
[I'm lonely / I want friends] ......
[Let's be friends] (1) I don't understand how you can adjust yourself to others. Friends? Comrades? I'll never need those.
(2) I seriously don't need any friends!
[Let's stay together forever] Being together with 6 others is already enough for me.
[I want to lose weight / I'm going on a diet] Why do you have to lose weight?
[I want to become cute] Why are you telling me?
[Compliment me] I don't know any compliments.
[Pay attention to me] It's "Please pay attention to me, Ichimatsu-sama", right?
[Come with me] I don't like the way you said that.
[I got rejected] Congratulations.
[Let's play] ...Don't wanna.
[How do you play?] I play... with the cats... and a piece of grass. (ネコジャラシ, green foxtail).
[Sing] (1) ... Don't wanna.
(2) Nyaanyaanya, nya nyanyanya nyaa nyaanano nyaanano (singing)
[Dance] How about you ask Shittymatsu?
[Do an impression] Of who? Osomatsu? Shittymatsu? Choromatsu? Juushimatsu? Todomatsu?
[Do your best] You think trash can do its best?
[Are you okay?] Of course not.
[Pleas do it] What did you want me to do? I forgot?
[Forgot] Ah, did you just think I'm trash? I'm trash. I'm garbage.
[Impossible] What is?
[Cool / Hot guy] (1) Even if you compliment garbage like me, I won't do anything in return.
(2) Thanks for being an ass-kisser.
[Dreamy / Amazing] (1) Even if you compliment garbage like me, I won't do anything in return.
(2) ...Not really.
[You're kind] ... Not really.
[Patting (head) / I support you] (1) Even if you compliment garbage like me, I won't do anything in return.
(2) That was so-so.
[There, there ( yoshiyoshi = like calming someone down)] Thanks.
[You're cute / You're pretty] (1) Is there something wrong with your eyes?
(2) What are you saying?
[It fits you] Are you insulting me?
[I (really) like you / Marriage] Hmmm, you have weird tastes...
[I love you] Thanks for that big lie.
[Go out with me] ...Impossible.
[Marry me] Do you enjoy making fun of trash?
[I want to get married] ...Do you own a cat?
[I hate you] It's fine if you want to belittle me more.
[I really hate you] I don't really want you to like me anyway.
[Annoying] Are you talking about Shittymatsu.
[You piss me off] Why yes, thank you.
[I don't get it / What?] I don't need you to understand though?
[Do you want something?] (1) Free/bored/nothing to do...
(2) Maybe I should go play with the cats...
[Why? / How?] I don't know either.
[Kiss] You want to catch a cold?
[Naked / Butt / Ecchi / S*x / Underwear / Horny / Girls] By all means, but make it rough.
[April Fool's] In the Matsuno household, it's April Fool's all year round.
[Halloween] Nyaa~on
[Trick or Treat] Please trick me.
[Christmas Eve] Hah?
[Valentine] For trash, it's just a normal day.
[White Day] For trash, it's just a normal day.

* When opening the app
Meeting me, how does it feel?
Do you want something from me?
Do you want something?

* Towards words he can't react to
I don't know...
I kinda don't understand.
Dunno.
Ah, dunno

* If the mic can't catch it correctly
Huh...? One more time.
Hmm? What was that?
Sorry, couldn't hear it.
Did you say something?