Leather

The title is a pun: it stitches together the start of Lea(kage Voltage) and the end of (Fur)ther. Before release, many players expected Further to be paired with another Doin song, Flew Far Faster, yielding the tidy name FFFF; instead the remix combined Leakage Voltage and Further. Korean fans jokingly call it "leather" the material, and the official Pump It Up chart channel once even translated the title that way. The core gimmick is that the two songs swap rhythms and melodies: Leakage Voltage is set to Further's irregular, constantly shifting meter, while Further's section is rebuilt around a steady beat. Unlike some patchwork remixes, Leather is widely praised as a polished piece that feels like a fresh song rather than a forced mashup.

In PHOENIX the levels are Single 18 / 21 / 24 and Double 22 / 26, charted by WINDFORCE. The original charts leaned heavily on hold notes, which inflated the MAX combo and let players clear without watching the gauge; with XX they were reverted to a tougher earlier version (the mid-chart hold-grabs were also made left-right symmetric). The S18 blends Further's S18 with Leakage Voltage's S17 and is easy for its level, though draining. The S21 drops the brutal twists of Leakage Voltage's S21 but keeps the fatigue of running nonstop at 200 BPM. The S24 is a stamina drain where sense-play matters most, living in the shadow of Bemera, the S24 stamina king. The D26 is one of the four classic entry-level 26 charts, packed with hold-grabs; PHOENIX adjusted the hold-note ticks and reworked the final run, raising the clear difficulty, yet it remains the most-cleared D26 and still holds the entry line.