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We report on time-series photometric observations in the earliest stages ofsuperoutbursts of the extreme dwarf novae, AL Com and WZ Sge, which started on2001 May after the 6 years quiescence and on 2001 July after the 23 yearsquiescence, respectively. We detected growth of ``early superhumps'' during theeach rising stage. Our observations reject the mass transfer instability forthe trigger of the superoutburst of WZ Sge stars, and show the existence ofsome relations between the ``early superhumps'' and the spiral structure, whichgive a hint of the origin of the ``early superhumps.''Comment: 4 pages, 4 figures, A&A macro in latex format, accepted to A&A  letter

First detection of the growing humps at the rapidly rising stage of dwarf novae AL Com and WZ Sge