Ufortunately I dont have a hardware to test it.
If you would have the opportunity to program the ATmega328P/ATmega32A Microcontroller using assembly (low level language), you would certainly become impressed and astonished to observe how hard and beautiful work the Arduino Developers have done to bring the I2C Bus (aka TWI Bus) Protocol into the High Level Programming paradigm.
It is my understanding that the Forum Members who do talk on the I2C Bus have learnt the protocol having done a lot of experiments using two UNOs and many kinds of I2C based devices. They have also spent a good amount of time in the Forum particularly on the I2C Bus related topics.
Therefore, I would like to request you to kindly arrange the hardware (2 UNOs) and learn yourself (also by taking help from the Forum) (performing experiments) the meanins of TWI bus Interrupt, Wire.requestFrom();, Wire.onRequest();, Wire.onReceive();, Wire.available();, Wire.read();, Wire.write();, and etc.
Thank you,