That explains the glass. Kita explains the opportunity to use it: she plays through the gap while Hitori works out what to do. You can see both parts in Aniplex’s official school-festival performance of “If I Could Be a Constellation”. This article contains spoilers for the first-season finale. Its illustrations are generated explanatory drawings, not frames captured from the anime.
A broken string and a tuning problem impose different limits
The trouble leaves Hitori unable to rely on her prepared fingering. A missing string removes notes she expected to play in those positions. A playable string that has slipped out of tune creates another problem: putting a finger at the familiar fret now produces the wrong pitch.
The glass cannot restore a snapped string. Hitori still needs a string that can vibrate. What it gives her is control over the sounding length of the strings she can use. She can adapt her line and place the contact where the desired pitch actually is.
With an ordinary fretted note, your finger pushes the string against a metal fret. The vibrating part extends from that contact point to the bridge. The fret stays in the same place when the string goes flat, so familiar fingering alone cannot correct the tuning error.
With slide technique, a hard, smooth object touches the string without pushing it down onto the frets. The object supplies the contact point. Moving it towards the bridge shortens the vibrating length and raises the pitch; moving away lowers it. Fender’s slide guide describes the light pressure and placement above the fret wire needed for clean, correctly pitched notes on a tuned guitar.
How far would a flat string need to shift?
Consider an ideal string with a 650 mm vibrating length when open. The twelfth fret is halfway along it, leaving 325 mm to the bridge. Halving the length produces an octave when tension and mass per unit length remain unchanged, as explained by UNSW’s vibrating-string model.
Now suppose that string’s open pitch drops by exactly one semitone. Playing at the usual twelfth-fret position also leaves the octave note one semitone flat. To reach the intended pitch with a slide, the sounding segment must be about 306.76 mm long. That puts the contact point 18.24 mm closer to the bridge than the twelfth fret — at the ideal thirteenth-fret position.
We calculated that example using equal temperament: a semitone corresponds to a frequency ratio of 21/12, so the required length is 325 ÷ 21/12. A separate calculation reproduced the result. The 650 mm length and one-semitone drop are chosen inputs, not measurements of Hitori’s guitar or the anime’s soundtrack. This is an ideal-string illustration, with constant tension during light contact; a real instrument also has setup and intonation imperfections.
The practical requirement is listening. A slide does not make a badly tuned instrument automatically sound correct. The player must hear the pitch and adjust its position. Heavy pressure can push the string into the frets, and unmuted strings can add noise. Those are playing skills; finding a glass cup supplies only the tool.
Nor does the technique require a last-second change to an open tuning. Taylor’s introductory slide lesson uses standard tuning. Open tunings can make slide chords convenient, while individual melodic notes remain possible in standard tuning. The scene’s improvised solution is therefore musically plausible without assuming an unseen retuning of the whole guitar.
Kita keeps the solo from becoming a stopped song
Rewatch the official performance from about 1:25. Kita continues playing while Hitori is occupied with her guitar. Around 1:42, Hitori is using the glass; the closer view at 1:47 makes its contact across the neck easy to see. These timestamps refer to the linked Aniplex clip, rather than the full episode.
Kita’s contribution is useful precisely because it gives Hitori something to play into. She does not need to fix the hardware or duplicate the planned solo to help. Maintaining the passage lets the guitarist search for a workable contact position while the audience still hears a performance.
There is a related, more domestic exchange in Senshi’s two tastings in Delicious in Dungeon: someone accustomed to providing for the group receives help from it. Here the assistance has a specific musical shape. The fill buys time, and Hitori uses that time to change technique.
Listen to the passage before the glass solo, then watch the left hand during its return. The altered sound is only half the recovery. The other half is the part of the song Kita keeps available for Hitori to rejoin.
