Bye-bye, Sai. (hey! it rhymes!) This simple phrase holds a certain charm and finality. It's like a gentle wave goodbye to someone or something named Sai. Maybe Sai is a friend, a pet, or just a passing acquaintance. The act of saying goodbye can be bittersweet. On one hand, it marks the end of a particular chapter or encounter. But on the other hand, it also opens the door to new possibilities and experiences. As we utter those two words, "Bye-bye, Sai," we might feel a tinge of sadness or a sense of relief. It all depends on the nature of our relationship with Sai. Nevertheless, this little rhyme serves as a memorable way to bid farewell and move on to the next phase of our lives.
Finally, the arc of Sai reaches its more or less necessary end. It has been a long time since Sai no longer truly fit the narrative. I feel that finally, Hikaru can mature as an individual. After Sai repeatedly nudged him that he would disappear soon, he finally vanishes after some demonstration games and after playing the new title holder who drunkenly asked Hikaru to play Sai.
But Sai can no longer offer any helping hand to Hikaru, and he feels that it is his time to go away. He cannot take over like he did with Torajiro, so he can finally rest easy, knowing that he fulfilled his purpose.
Hikaru is scared by Sai's abrupt departure, not having the same understanding as the reader about why he left. He is upset and searches everywhere for him. He takes a train to Hiroshima and visits his birthplace and grave in Innoshima. Back in Tokyo, Hikaru chooses to quit go altogether. Akira tries to prompt him on his choice and question his motives, but Hikaru is just too depressed.
At times, it does seem like the Sai-Hikaru relationship just didn't work. While it was a strong point in the beginning of the manga, it is definitely the weaker point in the last few volumes. I think their relationship was truly mishandled by the author. However, this is the redeeming moment, a good solution that will allow Hikaru to be his own person.
Second reading: Now, while I still agree with my initial thoughts on the volume, for certain, the finale of the Sai-Hikaru relationship hits a sensitive spot. The moment is emotional, it does strike hard and makes you tear a bit. That aspect is well done.