With the increasing use of adjuvant chemotherapy for treating early breast cancer, febrile neutropenia management has become crucial. Guidelines for febrile neutropenia management are mostly based on a Caucasian population survey although ethnic differences are reported in terms of adverse events. We survey the current status of febrile neutropenia and risk factors in Japanese female breast cancer patients receiving neoadjuvant and adjuvant chemotherapy regimens potential for febrile neutropenia. Subsequently, we plan to conduct a multicenter prospective cohort study involving 1000 patients with operable breast cancer. With the current state of oral antibiotics being routinely prescribed without hematology tests, we survey febrile neutropenia based on two different definitions, namely, true febrile neutropenia: ≥37.5°C and Grade 4 neutropenia, and surrogate febrile neutropenia: ≥37.5°C and oral antibiotic and antipyretic intake. The comparison of true febrile neutropenia and surrogate febrile neutropenia incidences is anticipated to provide information on the safety and feasibility of chemotherapy management without performing blood tests.