We know that the key to knowing all the VIPs in the Zodiac exam in Y1V4 was to crack the VIP pattern. In canon , the method Ryuen used to crack the pattern was by gathering the names of 6 VIPs in total , according to the rule mentioned in Y1V5 i.e. 2 VIPs from class B , 3 VIPs from his own class , and 1 VIP from class D. However , it was mentioned by Kiyotaka that the possibility of Ryuen cracking the whole pattern with just 3 VIPs exist , if you remember the details of the volume , leaving aside the method he told us about the way to crack the pattern with 6 VIPs by just collecting the VIP names. That means an alternative method to crack the VIP pattern with 3 VIPs exists , which Ryuen missed out on noticing. This post is about that method , another hidden plot in Y1V4.
To start , in case you are aware , the Zodiac groups from the exam are based on the Chinese Zodiac groups , numbered 1 to 12. The pattern of matching the Zodiac group to the alphabetical order of the students in a group's list , was according to the chronological order in which the Zodiac groups are arranged. That's the description the novel spoonfed to us , but now let's dive a little deeper.
This is the "compatible trio" chart of the Zodiac groups. : https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcT4dBC5IEzMHTmOLOlJwK4x3k0fZTxk-rEbYw&usqp=CAU
This is the Zodiac groups relationships chart , which gives us information on a Zodiac group's allies , secret friend and conflict animal : https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSmb8201QAb-I9UWKYSgJN1UYBHMNGkhgk70A&usqp=CAU
Now , go back to Y1V4 , and consider the classes which the VIP of each group belonged to. You will need to do the math as well as concentrated reading.
- Using the alphabetical order pattern , the VIP of the Cow group is Yume Kobashi of class B ,which Ryuen made an intentional wrong guess on. Similarly , doing the Math by looking at the results , the VIP of Monkey Group ( which Koenji ended ) is from class B.
-Rooster , Pig and Rat's VIP's are from class A , mentioned by Ryuen during targeting them.
- Rabbit ( Kei ) , Dragon ( Kushida ) , and Horse ( Minami )
- The groups remaining are 3 of class C and 1 of class B. Sheep , Dog , Snake , Tiger.
Now observe the compatibility trio charts closely. Remember this exam is all about patterns. If we consider Dog group as the VIP , the 4 compatibility trips classified by which class the VIP of the group belongs to , become as :
- Trio 1 : A , B , D
- Trio 2 : A , B , C
- Trio 3 : B , C , D
- Trio 4 : A , C , D
Now also observe the table of allies , secret friends and conflict animals' comparison with the main zodiac animal. If we input the VIPs' classes we know of in the table , it becomes something like this :
+------+----------------+---------------+-----------------+
| Main | Allied | Secret friend | Conflict animal |
+------+----------------+---------------+-----------------+
| A | D,B | B | D |
+------+----------------+---------------+-----------------+
| B | C,A | A | C |
+------+----------------+---------------+-----------------+
| C | D,B | A | B |
+------+----------------+---------------+-----------------+
| D | C,A | B | A |
+------+----------------+---------------+-----------------+
| D | A,B | A | B |
+------+----------------+---------------+-----------------+
| C | B,A | B | A |
+------+----------------+---------------+-----------------+
| D | C,B | C | A |
+------+----------------+---------------+-----------------+
| C | D,A | D | B |
+------+----------------+---------------+-----------------+
| B | A,D | C | C |
+------+----------------+---------------+-----------------+
| A | B,C | D | D |
+------+----------------+---------------+-----------------+
| B | C,D | D | D |
+------+----------------+---------------+-----------------+
| A | D,C | C | C |
+------+----------------+---------------+-----------------+
You can observe the pattern. When you do a comparison to the main zodiac group with allied animal , secret friend or conflict animal , none of them overlap even when you consider all 12 cases , all 48 combinations. This also includes the compatibility chart , where the combinations followed are A , B , C + A ,B ,D + A ,C ,D + B ,C ,D , EACH unique combination which covers all 4 cases. SO , what is the conclusion that we can derive from this discovery ?
First , the groups arranged according to the class the VIP of the group belongs to are as follows :
-Class A : Rat , Rooster , Pig
-Class B : Monkey , Cow , Dog
-Class C : Sheep , Tiger , Snake
-Class D : Rabbit , Dragon , Horse
Second , since the probability of such a match being a coincidence is EXTREMELY low ( even lower than the possibility of alphabetical order pattern being a coincidence which was canonically used in the story ) , this is a pattern in which the VIPs of the groups are arranged. Hence , in this case , what should be the inference ? It's that certain Zodiac signs are grouped together in accordance to the "classes" they belong to , and they're considered as one entity when the pattern is concerned. Hence , the "allies" , "secret friends" or "conflict animal" are always the groups from another class , since they're treated as someone different from them. So the rules in this case are :
So what is the method to crack the pattern in this case ? You just need to know your own class' 3 VIPs for that. Let's consider from class D's perspective. Their own VIPs were from Rabbit , Dragon and Horse groups. So what they do is make a chart about which groups' VIPs cannot share the same class. In their case , it would be like this :
Rooster - Monkey , Cow
Cow - Snake , Rooster , Rat , Sheep
Tiger - Dog , Pig , Monkey
Snake - Cow , Rooster , Monkey , Pig
Sheep - Pig , Cow
Monkey - Rat , Snake , Tiger
Rooster - Cow , Snake
Dog - Tiger
Pig - Sheep , Tiger , Snake
These are the groups whose VIPs WON"T be sharing a class. Then , they use the 3 VIPs of their own class they have at hand , to analyze the pattern they can find , and the alphabetical order anomaly is noticed. HOWEVER , at this point they still can't be sure whether this pattern is only restricted to their own class , or it is universal. Because it is entirely possible every class has a different pattern of VIP arrangement. That is the reason Ryuen had to take class D's and class B's VIPs to confirm that the pattern indeed applied to other classes as well. BUT , with this chart , they can verify their pattern. How ? The steps are :
This is how one can arrive at the root of the exam with only 3 VIPs , the more efficient method of doing it. And hints tell us that Kiyotaka knew about this. He talked about a way to arrive at the answer using just 3 VIPs , but didn't elaborate. He also said he could've used other means to score far more points than he did. He also said what he did in the Zodiac exam was the bare minimum required.
Kiyotaka could've ended the entire Zodiac exam on the first day itself
But he didn't , because his plan was to make Ryuen collide with him head on in V7 and personally defeat him , not go brute force on everything like that. And if it wasn't obvious , yes Ryuen missed out on catching this pattern , otherwise the entire exam would be over on the first day and every other class would get destroyed.
This concludes the hidden plot.