Puyo Puyo Tsu (ぷよぷよ通, Puyopuyo Tsū, also known as Puyo Puyo 2, Puyo Puyo Tsuu or Puyo Puyo 2: Tsuu) is the second instalment of the Puyo Puyo games; the sequel to Puyo Puyo, made in 1994 by Compile. Compile put more thought into this game after its predecessor became successful, but never knew how much of a turnaround the game would bring. Due to its highly acclaimed success, it became the most predominant game of the series. Though with many of its rules being experimental, the ability of Sousai and Rensa Sibari became a top hit immediately, thus creating longer matches for better gameplay. Also due to its successes, it became the most widely known multiplatform game in Japan, appearing in the Arcade, on major domestic consoles, on major handhelds, on the NEC PC98-01, on the PC, and on others.

The name of Puyo Puyo Tsu comes from an English pun, as "tsu" (通, tsū, meaning Expert) when spoken aloud sounds similar to the English word "two". Compile continued this pun for Puyo Puyo SUN and Puyo Puyo~n.

Just like the prequel, Puyo fall from the top of the screen in pairs, can be moved left and right, and can be rotated clockwise and counter-clockwise by 90°; if the third column from the left fills up to the top, the game is over. Different rules however played a factor within the game. The game also has different styles of playing for each version, including its newer features, explained below:

Sousai

The first extended rule added to this game was called Sousai (Garbage Countering). This will allow a player to counter and negate garbage being sent by the opponent with chains of their own. The idea with Sousai was to enable players to negate as many ojamas as possible before they fall, thus creating more of a challenge for all players.

The idea in which this worked is simple, say Player A scores a 4 rensa that sends 30 garbage, and Player B scores a 3 chain before garbage falls. Each value of garbage each chain is worth is used to negate that many garbage from Player A's 4 chains as a result. Chain 1 does 3 garbage damage, Chain 2 does 8 garbage damage, and Chain 3 does 9 garbage damage. From 30, 3 will be deducted first, then 8, then 9, creating a total of 20 garbage. In the prequel, this would be sent directly to the opponent, but in this game, 20 is taken away from the 30 waiting to fall, leaving 10 garbage to fall instead of 30 (as 30 - 20 = 10).

Sousai can also be used to send garbage back to the opponent, known as Garbage overflow. If Player A scores a 4 Chain that does 30 garbage, and Player B scores a 4 chain that does 36 garbage, the 30 from Player A will be completely negated and 6 would be sent back as the overflow. Power Rensa plays a huge part in Sousai, following the Power Rensa rule, and can negate and send garbage back to the opponent many a time.

Sousai can be seen as one sided too, however, as the player who has finished their chain can then begin to build another, whereas the player who is still countering with chains of their own may not be able to diminish all garbage, leaving leftovers to fall. On a critical scale, weak chains will mean certain doom if a Player scores a strong rensa of any type. Equally speaking, it will take a chain of equal proportions to keep the game flowing. Many pro players make sure that they are the last to attack, so that they follow behind to keep the game moving. Many players however, know that if the opponent is chaining, and the chain is fairly extensive (for example, 10 rensa), they can use the time it takes to create a few more steps on their readily built chain (say, five more steps on a 10 rensa of their own, making 15 rensa altogether), and then unleash that, to counter all garbage and send overflow back, and keep sending more garbage with each chain hit. The opponent can then quickly build a chain of their own to counter, to keep the garbage going back and forth in succession until one person fails to negate garbage to a minimal level and loses the game, keeping the fairness in the game. This term of throwing garbage between the players is called Puyo Tennis, as it's the knocking of garbage between each players pending grid before it eventually falls and that player loses.

Rensa Sibari

A custom rule that can also be applied to Puyo Puyo 2 is called Rensa Sibari (Chain Limit). When set to a particular number, each chain up to that number doesn't score anything, nor does it send garbage. If Rensa Sibari, for example, is set to 7, then no player can send garbage unless the chain hit is 7 rensa or higher. By default, it's turned off (or more notably, is set to 1, as all single rensa normally sends garbage), but can be set up to a maximum of 9 in this game.

In Puyo Pop Fever and later games, this setting can be set at any value between 1 and 20, where 20 makes it impossible to send any garbage, ideal for training and coaching sessions. This is because there is only enough room on the board for a maximum of 19 chains, though Puyo Puyo SUN is unique in having an extra row of "hidden" spaces, allowing a maximum of 20 chains.

Double-Rotation

A useful of this game is the ability to double rotate when stuck in-between columns. As with all current games that used this rule, it wasn't used in the prequel. If Player A has piece Red-Yellow falling from Column 3, and Columns 2 and 4 are filled to the top, then by pressing any rotate button twice, the puyos will flip, meaning that the piece would look Yellow-Red as opposed to Red-Yellow (Key: Top Puyo-Bottom Puyo -> A-B becomes B-A).

A way of escaping is also to place puyos over the top'. To do this, one must double rotate the puyo from the top of the screen as quickly as they can, and can use (if it isn't blocked), the hidden off-screen area to move from one column to another vacant column (Keep Columns 2 and 4 filled to the top, yet Column 5 is vacant, by double-rotating, and moving to the direction of Column 5, you can flip the puyos over the top of Column 4 and into Column 5). This doesn't always work, but can work for stalling if you need a bit of extra time to either get the coloured puyo you need to set off a chain, or to stall and let your opponent lose first (though they can use the same trick, so it's not always successful either).

Rule Henka (Grid Preset)

In Puyo Puyo 2, an experimental rule called Rule Henka was brought into the game. When turned on, as each game starts, different ojama presets will appear (see Ojama).

Kata Lock

Unlike Rensa Sibari, Kata Lock differs from negating garbage being sent. It does, moreover, disallow bonuses or special effects to happen until the selected number has been set (see Ojama). By default, it's set to off, but like with Rensa Sibari, you can set it to 9.

Zenkeshi (All Clear)

Another revolutionary idea that's been kept for every game since Puyo Puyo Tsu, is a bonus called Zenkeshi. When all puyos are cleared from your grid (including all garbage), yellow text will appear on the screen, reading "Zenkeshi" (全消し). If you send a chain after this has happened, it is worth the single chain amount plus 30 garbage.

Many top players can All Clear from 7 or more chains, and having a cleared field means you can easily build chains from the beginning. You also score 10000 points for all clearing too.

The fanfare used for this is an alternative version of the Compile bios theme. Sega retained this for the release of Minna de Puyo Puyo and Puyo Puyo Fever to show originality of the game. In Puyo Puyo Fever, when you all clear, instead of sending bonus damage, you are awarded a random preconstructed 4 chain, with which you can either set off for a quick attack, or use its foundation to build a stronger chain overall. Some people prefer this as it enables you to send roughly the same amount of garbage, but because you can build upon it. There are some that disagree, as the bonus, though it may seem one sided, can be used to strengthen the overall chain altogether, regardless of how many steps it is.