The Belle and Belle II experiments have collected a combined data sample of 1.4 abβ1 of π+πβ
collisions at center-of-mass energies near the Ξ₯(ππ) resonances, including a 19.6 fbβ1 sample taken
near the Ξ₯(10753) resonance. Recent results from Belle include evidence for βπ (2π) β Ξ₯(1π)π
and searches for βπ (2π) β πΎ πππ½ (1π) that probe spin-symmetry breaking in bottomonium
transitions. Belle II studies around the Ξ₯(10753) region explore the π+πβ β πππ (1π), πππ0 (1π),
and π+πβ Ξ₯(ππ) channels, providing new information on the structure of this state. Searches for
hidden-charm and hidden-strange pentaquarks in Ξ₯(1π, 2π) decays further extend the spectroscopy
program. These measurements highlight the growing capability of Belle II to study bottomonium
and exotic hadrons with high precision.

