(a) Light curve of YZ CMi during flares C and D. Filled squares (black) and triangles (red) represent continuum flux relative to the average flux observed with TESS and equivalent width of the Hα line observed with Nayuta/MALLS. The vertical axis indicates the time of observation in Barycentric Julian Date (BJD). The lower and upper horizontal axes represent continuum flux relative to the average stellar flux and equivalent width in unit of Å, respectively. (b) Line profile of the Hα emission line. The horizontal and vertical axes represent the Doppler velocity from the Hα line center and flux normalized by the continuum. Solid (black), dashed (green), and, dotted (purple) lines indicate the line profile before flares (BJD 2458502.135), that at the peak timing of flare C (BJD 2458502.177), and that of flare D (BJD 2458502.227). (c) Same as panel (b), but for the line profile changes from the pre-flare to the peak times of flare C and D. (d) Time evolution of the Hα line profile. The horizontal and vertical axes represent the Doppler velocity from the Hα line center and time of observation. The color map represents the line profile changes from the pre-flare profile. (Color online)