Things to Know Before You Start:

You'll need a big group of friends.

A large supply of your favorite drink

(And no, I am not promoting underage drinking ^_~ so make it legal, alright?).

Remove anything breakable from the room.

...and of course, all the Hana Yori Dango anime you have.

Take a sip...

If Tsukushi gets mad.
Twice if she yells/attempts to physically injure someone.
Three times if it's both.
Four times if it's at Doumyouji.

If Tsukushi says, "Hanazawa...Rui..."
Or if she says, "H-hanazawa Rui!"

If you think one of the characters needs psychiatric help.
Twice if it's Rui and/or Doumyouji.

When someone calls out, "Doumyouji-sama!"

If Tsukushi gets betrayed.
Twice if it's by Asai and co.

If Soujiro hits on a girl.
Twice if it's Yuki.

If Tsukushi can't make up her mind.

If Shizuka says "Rui!" in surprise.

If one or more of Tsukushi's classmates tries to gang up on her.
Twice if she fights back.

If Tsukushi talks about her "weed power" or calls herself a weed.
If Tsukushi taunts/scares/humiliates Asai and co.
If you can't seem to get "An Ordinary Sunday" out of your head.
If you've, by now, gotten into a debate about the identity of the guy in the closing credits.

If Soujiro and/or Arika say something perverted.
If Soujiro and/or Akira do something perverted ^_~.

If one or more people try to break Tsukushi and Doumyouji up.
If Tsukushi gets tricked.
If Doumyouji does something completely childish.

If when Shizuka chops off her hair, you think she kind of looks like a man.
Twice if you feel really guilty for thinking that because Shizuka's such a nice person.

If Doumyouji nearly kills someone.
If Uwara-sensei suddenly appears out of nowhere at just the right time.

If Tsukushi gets embarassed.
Twice if she blushes.

If Doumyouji misinterprets someone or says a phrase incorrectly.
Twice if people stare.
Three times if someone hits him upside the head for it.

If Tsukushi gets called "poor girl Makino".
Twice if the person throws "virgin" into that phrase.

If Tsukushi talks to one of her little toy things as if it were a close and trusted friend.
If Tsukushi says something into the green recorder-thing that has to do with Rui.

Tsukushi

1 drink if she mentioned wishing she could get through Eitoku peacefully
2 if she subsequently does (or has just done) something that makes that impossible
2 drinks if she actually looks happy at school!

1 drink if she slugs someone
2 if it's NOT Tsukasa 

1 drink if she refers to herself as the "weed" (Jp: Zassou)

1 drink every time she's knocked down and pinned to the ground by those weird grinning boys

Chug if no boy comes along to save her [never happens]

1 drink if she's kissed
2 if it's not Tsukasa
3 if she resists/pulls away [happens only once-with Junpei]
Chug if she REALLY kisses back! [ep 20, and ep 49]

1 drink when she calls a character by their first AND last name
2 if it's NOT Hanazawa Rui

1 drink if she yells "Yamete!!" more than 5 times in as many minutes [ep's 31 & 32]


Tsukasa

1 drink if he laughs like a pompous ass
2 if it's after episode 34

1 drink if he mispronounces a word/phrase/saying
2 if it's "bonbii" [his mispronunciation of "binbou"-poor]

1 drink if he shows of his superhuman strength

1 drink if when he SNAPS and goes RAAAGING BULL on someone

1 drink if he confesses his love to Tsukushi
2 if he kisses her
Chug if they do anything else [won't happen unless you're reading the manga, and barely happens there ^_^]

If they have sex, check yourself into the hospital, you've been drinking too much

1 drink every time he tries to kick Rui out of the F4

1 drink everytime he's teased for being a virgin
2 if it's NOT by Soujirou and/or Akira [happens in episode 33]

1 drink if he calls his mother "BABA" (old hag)

1 drink every time he shows up to rescue Tsukushi from whatever
2 drinks if he dosen't make it [cf. episode 44]

1 drink if he goes "nee-chan" after being socked/hit/punched/kicked


Rui

1 drink if he's on the emergency staircase
2 if we see that stock-footage shot of Tsukushi's knees as she runs toward the doorway

1 drink if he's playing the violin
Chug if he ever learns a new song :P

1 drink if he's humming

1 drink if he's actually with the F4
2 if he's actually participating in their conversation

1 drink if he calls Tsukushi "omoshiroi" (interesting), or "hen" (strange), or "okashii" (funny)

One drink if he tells Shizuka "aitakatta" (I wanted to see you)

One drink every time he mentions poop

One drink if he is not listening to a thing the other characer(s) on screen are saying

One drink if he kisses someone
2 if it's not Shizuka

1 drink evertime his hairdo changes

1 drink if he is ever sincerely happy [ep. 48] ^_^


Soujirou & Akira

1 drink when they discuss going to a club to pick out girls
2 if they are complaining that Tsukasa and/or Rui won't go out with them

1 drink if one eve appears without the other :P

1 drink if they do a little "roleplaying"
2 if Akira squeals like a girl or otherwise talks in falsetto. You'll need it. :P

1 drink if they're flirting with a girl
2 if it's Tsukushi
2 if Akira is flirting with a girl younger than she is
2 if Soujirou is flirting with two or more at one time

1 drink if they're giving Tsukasa "friendly advice" on how to win a girl over


Tsukushi's Friends

1 drink if Makiko or Yuuki say "Tsukushi..."/"Tsukushi-chan..." in that concerned tone of voice; or if Tsukushi says "Makiko-chan..."/"Yuuki..." in that i'm-so-glad-i-know-some-NORMAL-people voice ^_^

1 drink if Kazuya yells "Tsukushi-chaaaaaaan!" in his super-nasal way
2 if his arms are out airplane-style
3 if he has a pot on his head


Eitoku (the high school)

1 drink if Asai and company are badmouthing Tsukushi
2 if Tsukushi does something scary and makes them run away or scream "kyaaa!"

1 drink if they start squealing "Doumyouji-saaaan!" (you'll NEED it!)

1 drink if the teachers are complete zombies

1 drink if Sakurako says "Makino-senpaaaii!"
2 if you can't tell who's more nasal, her or Kazuya

1 drink every time Sakurako talks about how beautiful and cute she is

2 drinks if she ever does anything completely selfless :P

1 drink if she's talking to Kazuya :>

and for God's sake, chug if you ever see the F4 in class :P


Other Characters

1 drink if Tsukushi sucker-punches or otherswise injures her little brother

1 drink if Junpei brings up paper airplanes :P
2 if you can hear ants' screams... :P

1 drink if any character, previously thought to be good, reveals him/herself as bad, and vice versa [sakurako, junpei, sakurako revealed...]

Chug if Kaede ever shows emotion

1 drink if Shigeru completely obliviously puts Tsukushi in an uncomfortable position

1 drink every time someone gets a good slap :P


Cinematography/General

1 drink if any of the following symbols:
the cross-hatch pattern of the window bars on the hallway floor,
flower perals flying through the air
birds flying away

2 drinks if everytime the director pulls an i'm-so-cool:
the scene changes with the water washing over the previous scene...
Tsubaki's eyeball becomes the rotary driveway...
Tsukusho's tears become stars which become the waves of the ocean... etc.

2 drinks, then shoot the director, if Tsukasa shows up in a white tuxedo

Shoot the director anyway if they don't get a nice kiss in their last episode ::grrrr::