Actually, I have tried without luck to add bonus to the Tsumitate portion to max out this year.
Probably the problem is because the current setup is 50K for Rakuten Cash + 50K for Rakuten Card. Then, when I tried to add more for the Tsumitate portion, I get the error that I reached the limit for the Tsumitate part. Of course, (50K+50K)x12 would actually reach 1.2M for this year, however, the first month got only 33,333 yen in that Tsumitate portion. It seems to me that they have not taken in account the annual year limit reading the current amount in the Tsumitate part (in this case 33,333 yen) and adding up the number of yet to be done contributions (11 x 100K yen).
I wonder if editing the Rakuten Cash part to be less than 50K temporarily would let me add a one time contribution (bonus) to be withdraw from the Rakuten bank account.
Here are some screenshots I have taken so that it adds-up to my poor description of the problem
1. Above is my current setup for monthly contributions. (50K for Rakuten Cash + 50K for Rakuten Card)
2. The current process of this year Tsumitate is 33,333 yen.
3. I try to setup some extra Tsumitate bonus for the remaining 66,667 yen.
4. I get the error stating that I have reached the contribution limit.