AA-cup Breasts: You now have a pair of AA-cup sized breasts.
Eric(a): "I really hope they don't get any bigger. Hell they're already too big for a guy!"
A-cup Breasts: Your A-cup sized breasts might be small, but they are perky and perfectly shaped.
Eric(a): "What if I can never get rid of this pair? Am I going to have them for the rest of my life? I hope not."
B-cup Breasts: Your B-cup breasts give you an unmistakably feminine chest.
Eric(a): "Even if I escape, it's going to be hard to hide these. Shit, what am I going to do?"
C-cup Breasts: Your ample bosom is at least a C-cup.
Eric(a): "I can't believe these are mine. How the fuck did I end up in this situation!?"
D-cup Breasts: You gawk at your perfectly shaped D-cup breasts with a feeling of disbelief.
Eric(a): "Damn, I will never be able to hide these. I need to find a way of getting rid of these tits ASAP."
E-cup Breasts: Somehow you ended up with a firm pair of E-cup breasts. It is hard to imagine that these perky, all-natural boobs belong to you.
Eric(a): "...If I don't find a way of getting rid of these things, I'm so fucked!"
F-cup Breasts: Your breasts have grown to become a pair of shapely F-cups. You think some of the girls at camp may have been giving you jealous looks.
Eric(a): "I'm starting to think that I'm going to end up stuck with these. I hope that's not the case."
The Breast Growth Transformation is fairly straightforward; as a multi-stage transformation, each stage simply corresponds to the cup size of Eric(a)'s breasts. The first two stages are AA-cup and then A-cup, advancing a full cup size from then on with each additional stage. Each stage of the transformation also adds one Girl Score point.
Gaining
As a multi-stage transformation with a large number of stages there are correspondingly a great number of different ways to acquire this transformation. Each transformation event works differently, some giving a single cup size, some jumping directly to a certain cup size, and others enforcing a minimum cup size. Most will have certain restrictions in place as well, a common one being a limitation of a max E-cup with only a few transformations capable of going past that.
- Kaylin: If Eric(a) has rescued Kaylin from the Tomb of Garak she will be at the Centaur Camp. When saying bye she will note that you have been staring at her breasts. If Eric(a) is below C-cup she surmises that they are insecure about the size of their chest, if you agree then she will give you a potion that brings you directly to C-cup. Doing this first is advised if you wish to attain the largest breasts possible.
- Mana Burst: Using the Mana Burst spell gives a possibility of a transformation occurring overnight. This chance starts at 40% and carries over night to night, gaining 10% with each additional use until triggered. For breast size it can go up to B-cup.
- Tilia: Tilia can expand Eric(a)'s breasts up to four times. Each transformation has an upper limit of E-cup. More information can be found on each event on Tilia's page, but they are as follows:
- Nature Magic - First Lesson: Agreeing to Tilia's first lesson will gain one stage of the transformation as well as Entangling Vines
- Nature Magic - Second Lesson: Agreeing to Tilia's second lesson will gain one stage of the transformation as well as +10 MMP. If you took Tilia's panties during the Medical Exam event then she will force you to accept the lesson. If Eric(a) has the Sensitive Nipples Transformation then this will result in the Wood Nymph Game Over if done before the Big Tree without the Cutie Magic Transformation.
- Nature Magic - Boob Fight: Losing the boob fight with Tilia will gain one stage of the transformation. An acceptance point can also be gained if you decide that having boobs is not so bad. If Eric(a) is already at least an E-cup then a Penis Reduction Transformation will be gained instead.
- Succubus - Sneak Attack: This requires being on Natalie's route and gaining the Succubus Shift transformation. Choosing to "let it happen" during this event will gain a stage of this transformation along with a Succubus Behaviour point. The Bramblewood Earrings are also gained from this.
- Marianne: At the Watanabe Inn on the first day after stripping or being stripped, if Eric(a) is below an A-cup and has at least nine Girl Score so as to avoid the Caught In The Onsen Game Over then Marianne will transform Eric(a)'s breasts directly to an A cup.
- Lose to Slime Queen: Losing to the magico Slime Queen will cause her to attempt to make Eric(a) a cow, but is stopped before she can do it completely. If Eric(a) was below an E-cup they will gain one transformation stage. Additionally, Eric(a)'s minimum breast size will also raise by one stage at minimum, plus a second additional minimum stage if they have the Sensitive Nipples Transformation. There is also a stat loss for this at -5 MAT and -5 AGI.
- Siphon the Slime Queen's Core: Siphoning the Slime Queen's Core will raise Eric(a)'s minimum breast size by one stage if they did not previously lose to the Slime Queen. If the player did lose to the Slime Queen then the lost stats will be restored with no change to the minimum breast size. If Eric(a) was already at least at an E-cup then they will gain another stage of the transformation. If Eric(a)'s breast size was larger than the new minimum, but below an E-cup, then no breast growth will occur. This also grants the skills Slime Gown and Unnatural Vitality.
- Lose to Doom Flower, Siphon her Core: Losing to the magico Doom Flower reduces your breast size by one stage, has numerous stat losses, along with gaining the max Height Reduction Transformation. Siphoning the Plant Core later on restores the lost attributes and the lost breast size if any was lost.
- Siphon the Mimic Core (Natalie Route): If the player is on the Natalie route, then siphoning the Mimic Core will raise Eric(a) directly to a D-cup along with raising the minimum breast size to D-cup.
Removal
- Lose to Doom Flower: Losing to Doom Flower will reduce breast size by one stage if not already completely flat. This also gives max Height Reduction Transformation and -5 ATK, -5 DEF, and -5 AGI.
- Tilia: Winning Tilia's "Boob Fight" interaction allows you to choose one transformation to reverse, including one stage of breast growth. Tilia cannot reduce breast size below any minimum breast sizes enforced, and also cannot do it at all if Natalie's version of the Mimic Core was siphoned.
- Breast Reduction Elixir: The Breast Reduction Elixir is one possible reward for completing the Return to Mermaid Caves. Using it allows for the removal of one stage of this transformation.