Both characters are from two different entries in the series, and thus have never interacted in canon. However, in Danganronpa V3: Killing Harmony, the two of them share a number of interactions in the game's non-canon mode, Ultimate Talent Development Plan.
During the school festival, Kaede plays an exciting music piece, which earns her the praise of Ibuki. Kaede is happy to see that she came to her performance, and is a bit nervous as to what the Ultimate Musician thinks of her music. Ibuki tells her that even though the two of them play different genres, her piano performance rocked her very soul.
In another scene, Ibuki runs into Kaede and Sayaka Maizono. Kaede notes that she is super excited as usual. Ibuki says that the three of them were gathered together by the aura of a musical revolution, due to all three of them having a music-related talent. However, she also says that their styles of music are totally unique and clash with each other, which Kaede agrees with. The three girls still wish to collaborate in some way, and eventually reach a compromise. Although both Kaede and Sayaka express concern over Ibuki being in charge of writing lyrics.
Before the Christmas party, Ibuki decides to share her energy with Kaede before she goes up on stage to perform a collaborative piece she did with Sayaka. Kaede expresses gratitude that Ibuki came to cheer her on even though she won't be able to make it to their performance. However, Ibuki clarifies that she actually plans on attending both the concert and the Christmas party. Kaede promises her that she'll hear the best performance, which excites Ibuki.
In addition to both characters being musicians, they are also both known for being charismatic, encouraging and maintaining a level of optimism in any situation.
Because the two have never canonically met, the ship between them is not very popular and somewhat obscure. They seem to mostly be a platonic pairing as opposed to anything romantic.
- Interestingly, both Ibuki and Kaede were killed via asphyxiation. (They seemingly both died due to hanging, although it was later revealed that Ibuki was strangled to death before her body was hung.)
- They are both hinted at being bisexual, as they have expressed attraction to both genders.